Sending signal documentation is misleading

[Claude Paroz]

In the documentation of sending signals (​https://docs.djangoproject.com/en/dev/topics/signals/#sending-signals), there is an example where the sender parameter is filled with self (an instance), while most of the time, sender should be a class (at least it's the case in Django's own source code).

Unless I'm misunderstanding something, I suggest to replace sender=self by sender=self.__class__ in the example. And maybe specify that sender is a class most of the time. I can do the change if someone confirms that issue.

[Claude Paroz <claude@…>]

In d1f93e9c1e2c61bb06a6f99c80bd9437c5081f2d:

Fixed #22507 -- Clarified nature of the sender argument of signals

[Claude Paroz <claude@…>]

In abd68b5affaec35e941b49f1b0a4cb8d70c22d7b:

[1.7.x] Fixed #22507 -- Clarified nature of the sender argument of signals

Backport of d1f93e9c1e from master.

[Claude Paroz <claude@…>]

In b4b63b3832896d00bd9bd9e15c00cb7f1f9ac3ad:

[1.6.x] Fixed #22507 -- Clarified nature of the sender argument of signals

Backport of d1f93e9c1e from master.