Add !admin space roles subcommands: list, add, remove, assign, revoke,
require, unrequire, user, room, enable, disable, status. The remove
command uses cascade_remove_role macro to deduplicate member and room
cleanup loops. Role definitions, assignments, and room requirements
are managed via state events.
The first part of getting admin command docs on the website.
There's also the beginnings of manpage generation here, although it's
kinda sus and I'm not sure how it's supposed to work. I'll leave that to
anyone who wants to package it.
We introduce the beginings of the xtask pattern here - we do a lot of
file generation, I thought it would be best to avoid doing that on every
compilation. It also helps avoid lots of runtime deps.
We'll need to document generating this stuff & probably add pre-commit
hooks for it, though.
