docs: Docs fixes for 2.4.4 release (#3536)

This PR includes the following:

- Various link fixes identified on another pass
- Reinstating the sample docs until we can find a better home for them
(and moving them under their own samples folder)

It _does not_ include a fix for the broken external code links. These
aren't supported by the package docs tooling, and we need to discuss how
we're going to get around the issue before we merge/release the docs.

## Changelog

- Fixed: Various small issues with documentation.

## Testing and Documentation

- No tests have been added.
- Includes edits to existing public manual documentation.

## Backport

#3535

Author: jabbacakes

com.unity.netcode.gameobjects/Documentation~/TableOfContents.md

@@ -55,7 +55,6 @@
     * [Reliability](advanced-topics/message-system/reliability.md)
     * [RPC params](advanced-topics/message-system/rpc-params.md)
     * [RPC vs NetworkVariables](learn/rpcvnetvar.md)
-    * [RPC and NetworkVariable examples](learn/rpcnetvarexamples.md)
     * [RPC compatibility](advanced-topics/message-system/rpc-compatibility.md)
   * [Custom messages](advanced-topics/message-system/custom-messages.md)
   * [Connection events](advanced-topics/connection-events.md)
@@ -94,3 +93,11 @@
   * [Troubleshooting](troubleshooting/troubleshooting.md)
   * [Error messages](troubleshooting/error-messages.md)
 * [FAQ](learn/faq.md)
+* [Samples](samples.md)
+  * [Boss Room](samples/bossroom/bossroom-landing.md)
+    - [Boss Room](samples/bossroom/getting-started-boss-room.md)
+    - [Boss Room architecture](samples/bossroom/architecture.md)
+    * [NetworkObject parenting](samples/bossroom/networkobject-parenting.md)
+    * [Optimizing Boss Room](samples/bossroom/optimizing-bossroom.md)
+    * [NetworkRigidbody](samples/bossroom/networkrigidbody.md)
+    * [Spawn NetworkObjects](samples/bossroom/spawn-networkobjects.md)

com.unity.netcode.gameobjects/Documentation~/advanced-topics/bufferserializer.md

@@ -1,6 +1,6 @@
 # BufferSerializer
 
-`BufferSerializer<TReaderWriter>` is the bi-directional serializer primarily used for serializing within [`INetworkSerializable`](inetworkserializable.md) types. It wraps [`FastBufferWriter` and `FastBufferReader`](fastbufferwriter-fastbufferreader.md) to provide high performance serialization, but has a couple of differences to make it more user-friendly:
+`BufferSerializer<TReaderWriter>` is the bi-directional serializer primarily used for serializing within [`INetworkSerializable`](serialization/inetworkserializable.md) types. It wraps [`FastBufferWriter` and `FastBufferReader`](fastbufferwriter-fastbufferreader.md) to provide high performance serialization, but has a couple of differences to make it more user-friendly:
 
 - Rather than writing separate methods for serializing and deserializing, `BufferSerializer<TReaderWriter>` allows writing a single method that can handle both operations, which reduces the possibility of a mismatch between the two
 - `BufferSerializer<TReaderWriter>` does bound checking on every read and write by default, making it easier to avoid mistakes around manual bounds checking required by `FastBufferWriter` and `FastBufferReader`

com.unity.netcode.gameobjects/Documentation~/advanced-topics/client-anticipation.md

@@ -6,7 +6,7 @@ Client anticipation uses `AnticipatedNetworkVariable<T>` and `AnticipatedNetwork
 
 ## Overview
 
-Games with a server-authoritative architecture often face the problem of making the game feel responsive despite [latency](../learn/ladandpacketloss.md). For example, when a user wants to change the color of an object from green to blue they click a button in the UI, an RPC is sent to the server, and the server changes the object to blue. From the client's perspective, the object doesn't change to blue until the server responds to that message, resulting in a perceived delay for the user.
+Games with a server-authoritative architecture often face the problem of making the game feel responsive despite [latency](../learn/lagandpacketloss.md). For example, when a user wants to change the color of an object from green to blue they click a button in the UI, an RPC is sent to the server, and the server changes the object to blue. From the client's perspective, the object doesn't change to blue until the server responds to that message, resulting in a perceived delay for the user.
 
 ![](../images/sequence_diagrams/Anticipation/ServerAuthoritative.png)
 

com.unity.netcode.gameobjects/Documentation~/advanced-topics/custom-serialization.md

@@ -39,7 +39,7 @@ public static class SerializationExtensions
 
 The code generation for RPCs will automatically pick up and use these functions, and they'll become available via `FastBufferWriter` and `FastBufferReader` directly.
 
-You can also optionally use the same method to add support for `BufferSerializer<TReaderWriter>.SerializeValue()`, if you wish, which will make this type readily available within [`INetworkSerializable`](/advanced-topics/serialization/inetworkserializable.md) types:
+You can also optionally use the same method to add support for `BufferSerializer<TReaderWriter>.SerializeValue()`, if you wish, which will make this type readily available within [`INetworkSerializable`](serialization/inetworkserializable.md) types:
 
 ```csharp
 // The class name doesn't matter here.

com.unity.netcode.gameobjects/Documentation~/advanced-topics/fastbufferwriter-fastbufferreader.md

@@ -121,7 +121,7 @@ For performance reasons, by default, `FastBufferReader` and `FastBufferWriter` *
 > **In editor mode and development builds**, calling these functions records a watermark point, and any attempt to read or write past the watermark point will throw an exception. This ensures these functions are used properly, while avoiding the performance cost of per-operation checking in production builds. In production builds, attempting to read or write past the end of the buffer will cause undefined behavior, likely program instability and/or crashes.
 
 
-For convenience, every `WriteValue()` and `ReadValue()` method has an equivalent `WriteValueSafe()` and `ReadValueSafe()` that does bounds checking for you, throwing `OverflowException` if the boundary is exceeded. Additionally, some methods, such as arrays (where the amount of data being read can't be known until the size value is read) and [`INetworkSerializable`](inetworkserializable.md) values (where the size can't be predicted outside the implementation) will always do bounds checking internally.
+For convenience, every `WriteValue()` and `ReadValue()` method has an equivalent `WriteValueSafe()` and `ReadValueSafe()` that does bounds checking for you, throwing `OverflowException` if the boundary is exceeded. Additionally, some methods, such as arrays (where the amount of data being read can't be known until the size value is read) and [`INetworkSerializable`](serialization/inetworkserializable.md) values (where the size can't be predicted outside the implementation) will always do bounds checking internally.
 
 ## Bitwise Reading and Writing
 

com.unity.netcode.gameobjects/Documentation~/advanced-topics/message-system/rpc.md

@@ -218,4 +218,3 @@ There are a few other parameters that can be passed to either the `Rpc` attribut
 ## Additional resources
 
 * [RPC parameters](rpc-params.md)
-* [Boss Room RPC Examples](../../learn/bossroom/bossroom-actions.md)

com.unity.netcode.gameobjects/Documentation~/advanced-topics/object-pooling.md

@@ -16,10 +16,14 @@ You can register your own spawn handlers by including the `INetworkPrefabInstanc
 ```
 Netcode will use the `Instantiate` and `Destroy` methods in place of default spawn handlers for the `NetworkObject` used during spawning and despawning.  Because the message to instantiate a new `NetworkObject` originates from a Host or Server, both won't have the Instantiate method invoked. All clients (excluding a Host) will have the instantiate method invoked if the `INetworkPrefabInstanceHandler` implementation is  registered with `NetworkPrefabHandler` (`NetworkManager.PrefabHandler`) and a Host or Server spawns the registered/associated `NetworkObject`.
 
+<!-- Commenting this out until we can get external code references working
+
 The following example is from the Boss Room Sample. It shows how object pooling is used to handle the different projectile objects. In that example, the class `NetworkObjectPool` is the data structure containing the pooled objects and the class `PooledPrefabInstanceHandler` is the handler implementing `INetworkPrefabInstanceHandler`.
 
 ```csharp reference
 https://github.com/Unity-Technologies/com.unity.multiplayer.samples.coop/blob/v2.2.0/Assets/Scripts/Infrastructure/NetworkObjectPool.cs
 ```
 
 Let's have a look at `NetworkObjectPool` first. `PooledPrefabsList` has a list of prefabs to handle, with an initial number of instances to spawn for each. The `RegisterPrefabInternal` method, called in `OnNetworkSpawn`, initializes the different pools for each Prefab as `ObjectPool`s inside the `m_PooledObjects` dictionary. It also instantiates the handlers for each Prefab and registers them. To use these objects, a user then needs to obtain it via the `GetNetworkObject` method before spawning it, then return the object to the pool after use with `ReturnNetworkObject` before despawning it. This only needs to be done on the server, as the `PooledPrefabInstanceHandler` will handle it on the client(s) when the network object's `Spawn` or `Despawn` method is called, via its `Instantiate` and `Destroy` methods. Inside those methods, the `PooledPrefabInstanceHandler` simply calls the pool to get the corresponding object, or to return it.
+
+-->

com.unity.netcode.gameobjects/Documentation~/advanced-topics/physics.md

@@ -21,7 +21,7 @@ Some collision events aren't fired when using `NetworkRigidbody`.
 
 ## NetworkRigidbody and ClientNetworkTransform
 
-You can use NetworkRigidbody with the [`ClientNetworkTransform`](../components/networktransform.md#clientnetworktransform) package sample to allow the owner client of a NetworkObject to move it authoritatively. In this mode, collisions only result in realistic dynamic collisions if the object is colliding with other NetworkObjects (owned by the same client).
+You can use NetworkRigidbody with the [`ClientNetworkTransform`](../components/networktransform.md) package sample to allow the owner client of a NetworkObject to move it authoritatively. In this mode, collisions only result in realistic dynamic collisions if the object is colliding with other NetworkObjects (owned by the same client).
 
 > [!NOTE]
 > Add the ClientNetworkTransform component to your GameObject first. Otherwise the NetworkRigidbody automatically adds a regular NetworkTransform.
@@ -30,9 +30,7 @@ You can use NetworkRigidbody with the [`ClientNetworkTransform`](../components/n
 
 A common issue with physics in multiplayer games is lag and how objects update on basically different timelines. For example, a player would be on a timeline that's offset by the network latency relative to your server's objects. One way to prepare for this is to test your game with artificial lag. You might catch some weird delayed collisions that would otherwise make it into production.
 
-The ClientDriven [bitesize sample](../learn/bitesize/bitesize-clientdriven.md) addresses this by manually adding forces server-side to offer a buffer before an actual collision, but it still feels wobbly at times. However, this isn't really a solution.
-
-The best way to address the issue of physics latency is to create a custom `NetworkTransform` with a custom physics-based interpolator. You can also use the [Network Simulator tool](../../tools/network-simulator.md) to spot issues with latency.
+The best way to address the issue of physics latency is to create a custom `NetworkTransform` with a custom physics-based interpolator. You can also use the [Network Simulator tool](https://docs.unity3d.com/Packages/com.unity.multiplayer.tools@latest?subfolder=/manual/network-simulator) to spot issues with latency.
 
 ## Message processing vs. applying changes to state (timing considerations)
 
@@ -53,8 +51,8 @@ From this list of update stages, the `EarlyUpdate` and `FixedUpdate` stages have
 
 While `NetworkTransform` offers interpolation as a way to smooth between delta state updates, it doesn't get applied to the authoritative instance. You can use `Rigidbody.interpolation` for your authoritative instance while maintaining a strict server-authoritative motion model.
 
-To have a client control their owned objects, you can use either [RPCs](message-system/rpc.md) or [NetworkVariables](../basics/networkvariables.md) on the client-side. However, this often results in the host-client's updates working as expected, but with slight jitter when a client sends updates. You might be scanning for key or device input during the `Update` to `LateUpdate` stages. Any input from the host player is applied after the `FixedUpdate` stage (i.e. physics simulation for the frame has already run), but input from client players is sent via a message and processed, with a half RTT delay, on the host side (or processed 1 network tick + half RTT if using NetworkVariables). Because of when messages are processed, client input updates run the risk of being processed during the `EarlyUpdate` stage which occurs just before the current frame's `FixedUpdate` stage.
+To have a client control their owned objects, you can use either [RPCs](message-system/rpc.md) or [NetworkVariables](../basics/networkvariable.md) on the client-side. However, this often results in the host-client's updates working as expected, but with slight jitter when a client sends updates. You might be scanning for key or device input during the `Update` to `LateUpdate` stages. Any input from the host player is applied after the `FixedUpdate` stage (i.e. physics simulation for the frame has already run), but input from client players is sent via a message and processed, with a half RTT delay, on the host side (or processed 1 network tick + half RTT if using NetworkVariables). Because of when messages are processed, client input updates run the risk of being processed during the `EarlyUpdate` stage which occurs just before the current frame's `FixedUpdate` stage.
 
 To avoid this kind of scenario, it's recommended that you apply any changes received via messages to a Rigidbody _after_ the FixedUpdate has run for the current frame. If you [look at how `NetworkTransform` handles its changes to transform state](https://github.com/Unity-Technologies/com.unity.netcode.gameobjects/blob/a2c6f7da5be5af077427eef9c1598fa741585b82/com.unity.netcode.gameobjects/Components/NetworkTransform.cs#L3028), you can see that state updates are applied during the `Update` stage, but are received during the `EarlyUpdate` stage. Following this kind of pattern when synchronizing changes to a Rigidbody via messages will help you to avoid unexpected results in your Netcode for GameObjects project.
 
-The best way to address the issue of physics latency is to create a custom `NetworkTransform` with a custom physics-based interpolator. You can also use the [Network Simulator tool](../../tools/network-simulator.md) to spot issues with latency.
+The best way to address the issue of physics latency is to create a custom `NetworkTransform` with a custom physics-based interpolator. You can also use the [Network Simulator tool](https://docs.unity3d.com/Packages/com.unity.multiplayer.tools@latest?subfolder=/manual/network-simulator) to spot issues with latency.

com.unity.netcode.gameobjects/Documentation~/advanced-topics/reconnecting-mid-game.md

@@ -64,12 +64,10 @@ Depending on your game, you might want to add the following features as well:
 
 ## Automatic reconnection example
 
-Check out the [Boss Room sample](../learn/bossroom/getting-started-boss-room.md) for an example implementation of automatic reconnection.
 
 The entry point for this feature is in [this class](https://github.com/Unity-Technologies/com.unity.multiplayer.samples.coop/blob/v2.2.0/Assets/Scripts/ConnectionManagement/ConnectionState/ClientReconnectingState.cs). Boss Room's implementation uses a state inside a state machine that starts a coroutine on entering it ( `ReconnectCoroutine`) that attempts to reconnect a few times sequentially, until it either succeeds, surpasses the defined maximum number of attempts, or is cancelled. (Check out `OnClientConnected`, `OnClientDisconnect`, `OnDisconnectReasonReceived`, and `OnUserRequestedShutdown`.)
 
 The reconnecting state is entered when a client disconnects unexpectedly. (Check out `OnClientDisconnect` in [this class](https://github.com/Unity-Technologies/com.unity.multiplayer.samples.coop/blob/v2.2.0/Assets/Scripts/ConnectionManagement/ConnectionState/ClientConnectedState.cs))
 
 > [!NOTE]
 > This sample connects with [Lobby](https://docs.unity.com/lobby/unity-lobby-service-overview.html) and [Relay](https://docs.unity.com/relay/get-started.html) services, so the client must make sure it has left the lobby before each reconnection try.
-> For more information about how Boss Room leverages Lobby and Relay, refer to [Getting Started with Boss Room](../learn/bossroom/getting-started-boss-room.md#register-the-project-with-unity-gaming-services-ugs).

com.unity.netcode.gameobjects/Documentation~/advanced-topics/session-management.md

@@ -23,6 +23,8 @@ The best way to reconnect players depends on your game. For example, if you use
 
 In cases where we don't use the Player Object approach and instead manually attribute client ownership to `NetworkObject`(s), we can keep the objects that a player owns when they disconnect, and set the reconnected player as their new owner. To accomplish this, the only data we would need to keep would be the mapping between those objects and their owning player's identifier, then when a player reconnects we can use this mapping to set them as the new owner. This mapping can be as simple as a dictionary mapping the player identifier with the `NetworkObjectId`(s) of the `NetworkObject`(s) they own. Then, in the `OnClientConnectedCallback` from the `NetworkManager`, the server can set the ownership of these objects.
 
+<!-- Commenting this out until we can get external code references working
+
 Here is an example from the Boss Room sample, showing some simple session management. The game uses the Player Object approach and a GUID to identify unique players.
 
 ```csharp reference
@@ -36,3 +38,5 @@ In this case, since game sessions are quite short, the session data is only clea
 This code is in Boss Room's utilities package so it can be easily reused. You can add this package via the `Package Manager` window in the Unity Editor by selecting `add from Git URL` and adding the following URL: "https://github.com/Unity-Technologies/com.unity.multiplayer.samples.coop.git?path=/Packages/com.unity.multiplayer.samples.coop#main"
 
 Or you can directly add this line to your `manifest.json` file: "com.unity.multiplayer.samples.coop": "https://github.com/Unity-Technologies/com.unity.multiplayer.samples.coop.git?path=/Packages/com.unity.multiplayer.samples.coop#main"
+
+-->