Update documentation and auto-generate list of commands and descriptions

[GeckoEidechse]

There's currently some documentation on Reaper in the docs/ folder but it's heavily outdated.
To prevent it from turning stale again quickly after updating it, we should look into auto-generating it.
There's probably some tool out there that does that by just looking at the functions with decorators or something like that.

Ideally we would use such a tool so that we only have to manually maintain as little documentation for Reaper as possible.