Update README with basic usage.

Author: devoxin

README.md

@@ -1,2 +1,107 @@
 # lavaplayer-youtube-source
 A rewritten YouTube source manager for Lavaplayer.
+
+This source aims to provide robustness by leveraging multiple InnerTube clients
+for requests. Where one client fails, another will try to load the request.
+Which clients are used is entirely configurable.
+
+## common
+This module provides the base source manager, which can be used with any
+`com.sedmelluq.discord.lavaplayer` packages still on major version `1`.
+
+Example usage:
+```java
+YoutubeAudioSourceManager youtube = new YoutubeAudioSourceManager();
+// Optionally, you may instantiate the source with a custom options, such as toggling use of searching, and clients.
+YoutubeAudioSourceManager youtube = new YoutubeAudioSourceManager(/*allowSearch:*/ true, new Client[] { new Music(), new Web(), new Android() });
+```
+
+You may also extend the `Client` interface to support additional InnerTube clients. There are a few abstract classes to
+make this easier, notably, `MusicClient` (for `music.youtube.com` InnerTube clients), `NonMusicClient` (for youtube.com
+innertube clients) and `StreamingNonMusicClient` (for clients that can be used to stream videos).
+
+Support for IP rotation has been included, and can be achieved using the following:
+```java
+AbstractRouterPlanner routePlanner = new ...
+YoutubeIpRotatorSetup rotator = new YoutubeIpRotatorSetup(routePlanner);
+
+rotator.forConfiguration(youtube.getHttpInterfaceManager(), false)
+    .withMainDelegateFilter(null) // This is important, otherwise you may get NullPointerExceptions.
+    .setup();
+```
+
+## lldevs
+This modules expands on `common` by providing additional support for
+Lavaplayer `2.x` clients, such as [Lavalink-Devs/Lavaplayer](https://github.com/lavalink-devs/lavaplayer).
+Such features currently include thumbnail support within `AudioTrackInfo`.
+Additional clients are included that provide access to this additional information.
+These clients are suffixed with `Thumbnail`, such as `WebWithThumbnail`, `AndroidWithThumbnail` etc.
+
+Example usage:
+```java
+// same as the 'common' module but there are additional clients that provide video thumbnails in the returned metadata.
+YoutubeAudioSourceManager youtube = new YoutubeAudioSourceManager(/*allowSearch:*/ true, new Client[] { new MusicWithThumbnail(), new WebWithThumbnail(), new AndroidWithThumbnail() });
+```
+
+## plugin
+This module serves as the plugin for use with [Lavalink](https://github.com/lavalink-devs/lavalink).
+
+To use this plugin with Lavalink, you must declare the dependency.
+```yaml
+lavalink:
+  # ...
+  plugins:
+    # replace VERSION with the current version as shown by the Releases tab.
+    - dependency: "com.github.lavalink-devs.lavaplayer-youtube-source:plugin:VERSION"
+      repository: "https://jitpack.io"
+```
+
+Configuring the plugin:
+```yaml
+plugins:
+  youtube:
+    enabled: true
+    clients: ["MUSIC", "ANDROID", "WEB"]
+```
+
+> [!IMPORTANT]
+> You must make sure to disable the built-in YouTube source like so:
+```yaml
+lavalink:
+  server:
+    sources:
+      youtube: false
+```
+
+Existing options, such as `ratelimit` and `youtubePlaylistLoadLimit` will be picked up automatically by the plugin,
+so these don't need changing.
+
+## Available Clients
+Currently, the following clients are available for use:
+
+- `MUSIC`
+  - Provides support for searching YouTube music (`ytmsearch:`)
+- `WEB`
+- `ANDROID`
+- `ANDROID_TESTSUITE`
+  - NOTE: This client does NOT support loading of mixes or playlists.
+    It is advised not to use this client on its own for that reason, if playlists and mix support is required.
+- `IOS`
+  - NOTE: This client does not receive Opus formats, so transcoding is required. This can
+    increase resource consumption. It is recommended not to use this client unless it has
+    the least priority (specified last), or where hardware usage is not a concern.
+- `TVHTML5EMBEDDED`
+  - This client is useful for playing age-restricted tracks. Do keep in mind that, even with this
+    client enabled, age-restricted tracks are **not** guaranteed to play.
+
+## Migration from Lavaplayer's built-in YouTube source
+This client is intended to be a drop-in replacement, however there are a couple of things to note:
+
+- This source's class structure differs so if you had custom classes that you were initialising
+  the source manager with (e.g. an overridden `YoutubeTrackDetailsLoader`), this **is not** compatible
+  with this source manager.
+
+- Support for logging into accounts as a means of playing age-restricted tracks has been removed, with the
+  `TVHTML5EMBEDDED` client instead being the preferred workaround. There were a large number of
+  reasons for this change, but not least the fact that logging in was slowly becoming problematic and deprecated
+  on the YouTube backend. The amount of code to support this feature meant that it has been axed.