xmonad: Added configs and docs

* Added XMonad section to readme which specifies the installation of
  custom infoboard configuration.
* Added custom xmonad configuration scripts to `misc/xmonad`

Signed-off-by: mr.Shu <mr@shu.io>

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@martin-sucha nove masiny maju xmonady, preto cely tento pull request. Zrejme by sa patrilo tie konfiguraky niekde v repe, niesom si ale isty, ci prave v tomto priecinku.