Provide a list of notifications

[KingSupernova31]

Your Godot version:
N/A

Issue description:
The page on notifications doesn't actually tell the reader what the available notifications are, making it rather useless.

I thought a list might be on one of the two constants pages, since constants do exist for them, but nope, not there either.

URL to the documentation page (if already existing):
https://docs.godotengine.org/en/stable/tutorials/best_practices/godot_notifications.html
https://docs.godotengine.org/en/stable/classes/[email protected]#constants
https://docs.godotengine.org/en/stable/classes/class_%40globalscope.html

[AThousandShips]

This would be quite difficult to create and maintain as notifications aren't centralized, so we would need some way to gather all the notifications and put them in some list and then use that, or it would involve a lot of work to keep such a list up to date

I'm not sure that having a central list of these makes sense, IMO they make more sense where they are, a central list would easily be confusing and cluttered

[KingSupernova31]

This Reddit comment describes an automated way to gather most notifications. And if descriptions are already spread out across existing documentation pages, they can just be gathered from there.

More generally, "this feature is hard to document, therefore we won't" is just a terrible design ethos for any product. If the feature is important to have available to users, then it's also important to document so that the users are actually capable of using it. If it's not worth the trouble of letting users know how to use the feature, why have it at all?

Where they are right now is "spread out across 50 different pages that can't easily be searched". I'm not sure why this would be more convenient than a single list.