Add myself as maintainer

Author: cez81

MAINTAINERS

@@ -14,3 +14,4 @@ Thibault Meyer <meyer.thibault@gmail.com> (@0xbaadf00d)
 Thomas Boerger <thomas@webhippie.de> (@tboerger)
 Antoine Girard <sapk@sapk.fr> (@sapk)
 Lauris Bukšis-Haberkorns <lauris@nix.lv> (@lafriks)
+Jonas Östanbäck <jonas.ostanback@gmail.com> (@cez81)