vimrc as markdown

Still pretty far from being finished, and could also use a second pair
of eyes to check for outright wrong stuff.
inline-diff script
gitconfig as markdown

Probably more than halfway there.
Examples of `git lg` output
Add `git pr`
Correctly quote input variables

Apparently I put this version online without actually testing, so now it
does not blow up when your regular expression or path contains blanks.
Add `scrolloff`, remove some old mbe settings