Docs for anti-spam functions

[Tawmy]

This is an annoying one, but necessary, even for QA.

Anti-raid in this bot is obscure to configure. Using it is supposed to be simple, under the hood it's complex - there's various, non-self explantory configuration options.

The docs need sections for the following:

• All configuration options (what they do, what kind of values they accept, an example)
• Usage of the anti-spam functions in case of a raid
• Any other parts of the anti-spam module (complete in refinement)