Provide comprehensive context regarding extensible features and listeners in Addon documentation

[aryan-soni]

After the changes in #1379, the Addon documentation is missing two important aspects:

1. It should contain examples on how to extend every single feature that can be enhanced (further details in this comment).
2. It should contain an example on how an addon can instantiate multiple listeners (relevant discussion linked here).

[github-actions]

This issue is being marked as stale because there was no activity in the last 2 months