[xmonad] Preparing for v0.12 Release

[Peter Jones]

adam vogt <vogt.adam at gmail.com> writes:
> It seems like CHANGES.md is a slightly less detailed version of
> https://wiki.haskell.org/Xmonad/Notable_changes_since_0.11 . Probably they
> could reference each other, if they both should continue to exist.

I've pulled in the notes from the wiki and added additional details:

  https://github.com/pjones/xmonad-contrib/blob/release-0.12/CHANGES.md

-- 
Peter Jones, Founder, Devalot.com
Defending the honor of good code