Deprecate the wiki in favour of in-tree documentation

[Half-Shot]

We're going to be freezing the wiki going forward in favour of the documentation hosted in the git tree.

The reasons for doing so are that we favour the ability to:

• Review changes to the documentation so that we can verify accuracy before it is published.
• Ensure that documentation is tied to a version, rather than it potentially falling out of date.
• Give the team more control over the presentation of the documentation e.g. mdbook has a much nicer search interface.
• Inline documentation with released versions of the code, so that users may look up docs simply by reading from the docs/*.md area.

The wiki won't be going anywhere for the time being as the new documentation is not complete, but any new changes should now be made to the documentation. As maintainers, we will be trying to quickly get the new documentation up to speed.

Thanks for your patience and help!

[Mikaela]

What is the new location for https://github.com/matrix-org/matrix-appservice-irc/wiki/End-user-FAQ particularly using NickServ from Matrix which regularly comes up?

[Half-Shot]

@Mikaela We're moving away from a "FAQ" style document as it ends up being an unorganised list of headings. The current equivalent is https://matrix-org.github.io/matrix-appservice-irc/latest/usage.html (for your particular example https://matrix-org.github.io/matrix-appservice-irc/latest/usage.html#authentication).

If you think our text isn't good enough, feel free to adjust it via PR :).

[Mikaela]

I do think so. The section you link me to says that there is a !username command, it doesn't tell me how do I also specify a password which is documented a couple of sections up in "customizing your IRC experience" which will fail whenever the nickname is already in use during connection as there is no mention of storing username: as the beginning of the password. There is also no hint that the !username and !storepass work together.

I have no idea how to start fixing it.