Improving the contributing to ghc experience

[Moritz Angermann]

> You describe quite a lot there and I do wonder whether it might be
> helpful to break apart some of these ideas.

That might very well be. Maybe this proposal outgrows itself and needs
to be split into multiple proposals down the line? I’d suggest to 
facilitate the initial feedback in the current one to get a better grip
on what we are up against :)