[TASK] Document the supported selector types.
[TASK] Document the supported selector types.

iFixit/emogrifier,Seldaek/emogrifier,MyIntervals/emogrifier,Synchro/emogrifier,sanderkruger/emogrifier,jjriv/emogrifier,OzzyCzech/emogrifier,ricardofiorani/emogrifier,ernsto/emogrifier