New module that allows for having a configurable border position around
windows. Originally found in a comment by L. S. Leary in [1]. Enough
people have requested this on IRC in recent memory to warrant a proper
module.
[1]: https://github.com/xmonad/xmonad/issues/152#issuecomment-362716434
Co-authored-by: L. S. Leary <LSLeary@users.noreply.github.com>
