Improve links consistency

Now when talking about the `Actor` class, a link to the class is used
more consistently. When mentioning the `_run()` method, a link to the
"The `_run()` Method" section is provided too. When mentioning frequenz
channels, we link using the module instead of using URL. This improves
consistency but also makes sure we link to the version the SDK is
currently using.

Signed-off-by: Leandro Lucarella <[email protected]>

Author: llucax

src/frequenz/sdk/actor/__init__.py

@@ -31,17 +31,17 @@
 provides a straightforward way to implement actors. It shares similarities with
 the traditional actor programming model but also has some unique features:
 
-- **Message Passing:** Like traditional actors, our Actor class communicates
-  through message passing. Even when no particular message passing mechanism is
-  enforced, the SDK uses [Frequenz Channels][frequenz.channels] for communication.
+- **Message Passing:** Like traditional actors, our [`Actor`][frequenz.sdk.actor.Actor]
+  class communicates through message passing. Even when no particular message passing
+  mechanism is enforced, the SDK actors use [`frequenz.channels`][] for communication.
 
 - **Automatic Restart:** If an unhandled exception occurs in an actor's logic
-  (`_run` method), the actor will be automatically restarted. This ensures
+  ([`_run()`][_run] method), the actor will be automatically restarted. This ensures
   robustness in the face of errors.
 
 - **Simplified Task Management:** Actors manage asynchronous tasks using
-  [`asyncio`][]. You can create and manage tasks within the actor, and the `Actor`
-  class handles task cancellation and cleanup.
+  [`asyncio`][]. You can create and manage tasks within the actor, and the
+  [`Actor`][frequenz.sdk.actor.Actor] class handles task cancellation and cleanup.
 
 - **Simplified lifecycle management:** Actors are [async context managers] and also
   a [`run()`][frequenz.sdk.actor.run] function is provided.
@@ -148,14 +148,13 @@ async def _run(self) -> None:
 ## Communication
 
 The [`Actor`][frequenz.sdk.actor.Actor] class doesn't impose any specific way to
-communicate between actors. However, [Frequenz
-Channels](https://github.com/frequenz-floss/frequenz-channels-python/) are always used
-as the communication mechanism between actors in the SDK.
+communicate between actors. However, [`frequenz.channels`][] are always used as the
+communication mechanism between actors in the SDK.
 
 ## Implementing an Actor
 
 To implement an actor, you must inherit from the [`Actor`][frequenz.sdk.actor.Actor]
-class and implement the abstract `_run()` method.
+class and implement the abstract [`_run()`][_run] method.
 
 ### The `_run()` Method
 
@@ -174,19 +173,19 @@ class and implement the abstract `_run()` method.
 [`cancel()`][frequenz.sdk.actor.Actor.cancel] method (which will cancel all the tasks
 created by the actor) and will wait for them to finish.
 
-This means that when an actor is stopped, the `_run()` method will receive
+This means that when an actor is stopped, the [`_run()`][_run] method will receive
 a [`CancelledError`][asyncio.CancelledError] exception. You should have this in mind
 when implementing your actor and make sure to handle this exception properly if you need
 to do any cleanup.
 
 The actor will handle the [`CancelledError`][asyncio.CancelledError] exception
-automatically if it is not handled in the `_run()` method, so if there is no need for
-extra cleanup, you don't need to worry about it.
+automatically if it is not handled in the [`_run()`][_run] method, so if there is no
+need for extra cleanup, you don't need to worry about it.
 
-If an unhandled exception is raised in the `_run()` method, the actor will re-run the
-`_run()` method automatically. This ensures robustness in the face of errors, but you
-should also have this in mind if you need to do any cleanup to make sure the re-run
-doesn't cause any problems.
+If an unhandled exception is raised in the [`_run()`][_run] method, the actor will
+re-run the [`_run()`][_run] method automatically. This ensures robustness in the face of
+errors, but you should also have this in mind if you need to do any cleanup to make sure
+the re-run doesn't cause any problems.
 
 ???+ tip
 
@@ -197,8 +196,9 @@ class and implement the abstract `_run()` method.
 
 ### Spawning Extra Tasks
 
-Actors run at least one background task, created automatically by the `Actor` class. But
-`Actor` inherits from [`BackgroundService`][frequenz.sdk.actor.BackgroundService], which
+Actors run at least one background task, created automatically by the
+[`Actor`][frequenz.sdk.actor.Actor] class. But [`Actor`][frequenz.sdk.actor.Actor]
+inherits from [`BackgroundService`][frequenz.sdk.actor.BackgroundService], which
 provides a few methods to create and manage extra tasks.
 
 If your actor needs to spawn extra tasks, you can use
@@ -443,9 +443,9 @@ async def main() -> None:  # (6)!
 1. We define an `EchoActor` that receives messages from two channels and sends
     them to another channel.
 
-2. We implement the `_run()` method that will receive messages from the two channels
-    using and send them to the output channel. The `run()` method will stop if a `False`
-    message is received.
+2. We implement the [`_run()`][_run] method that will receive messages from the two
+    channels using and send them to the output channel. The `run()` method will stop if
+    a `False` message is received.
 
 3. We create the channels that will be used with the actor.
 
@@ -487,8 +487,8 @@ async def main() -> None:  # (6)!
 
 14. Since `selected.value` is `False`, the loop will break.
 
-15. The `_run()` method will finish normally and the actor will be stopped, so the
-    [`run()`][frequenz.sdk.actor.run] function will return.
+15. The [`_run()`][_run] method will finish normally and the actor will be stopped, so
+    the [`run()`][frequenz.sdk.actor.run] function will return.
 
 16. We close the `echo_channel` to make sure the `echo_receiver` will stop receiving
     messages after all the queued messages are consumed (otherwise the step 17 will
@@ -508,6 +508,7 @@ async def main() -> None:  # (6)!
 ```
 
 [async context manager]: https://docs.python.org/3/reference/datamodel.html#async-context-managers
+[_run]: #the-_run-method
 """
 
 from ..timeseries._resampling import ResamplerConfig