scripts: Include xmonad{ctl,propread}.hs in the release tarball
scripts: Include xmonad{ctl,propread}.hs in the release tarball

Last year I thought a bit about making this an actual `executable` in
xmonad-contrib.cabal, but decided against it. Unfortunately I can't
remember why. So let's do the bare minimum to at least ship it now, and
if I remember or if anyone has any ideas, we can do the next step or
document why not.

Fixes: https://github.com/xmonad/xmonad-contrib/issues/734

xmonad/xmonad-contrib,xmonad/xmonad-contrib