WIP: edit style guide

[guillermooo]

@FichteFoll In my opinion, the kbd role looks to ugly in tables. I think regular text looks much nicer.

This is not ready to merge, though.

[FichteFoll]

Btw, we can override the CSS of the rtd theme. I did this in a local branch already but didn't push yet. I hope to finish work on menu docs tomorrow (which is what I did it for) so we can get that over with.

I'd have to check how it actually looks myself though.

[FichteFoll]

If we use the :menuselection: rule we can get rid of the unicode arrow entirely. According to the sphinx docs we should also be leaving out trailing ellipses.