maintainer tools documentation updates
The previous change was overhauling the structure, now start making content changes. There's still more to do, but I ran out of steam here a bit, so let's get these moving forward.
There are some subtle tweaks to repository information and access requests, but mostly it's just cleanups and fixes.
FYI @mripard @mlankhorst @tzimmermann @rodrigovivi @dolphin @tursulin @thomash @demarchi