Added docs to get() & require() ops, plus get() now returns None if the var isn't found.
Added docs to get() & require() ops, plus get() now returns None if the var isn't found.

akaariai/fabric,getsentry/fabric,felix-d/fabric,bitmonk/fabric,pashinin/fabric,qinrong/fabric,rbramwell/fabric,mathiasertl/fabric,hrubi/fabric,MjAbuz/fabric,haridsv/fabric,opavader/fabric,sdelements/fabric,cmattoon/fabric,kxxoling/fabric,cgvarela/fabric,bitprophet/fabric,xLegoz/fabric,rodrigc/fabric,StackStorm/fabric,bspink/fabric,tekapo/fabric,SamuelMarks/fabric,amaniak/fabric,rane-hs/fabric-py3,ericholscher/fabric,fernandezcuesta/fabric,elijah513/fabric,itoed/fabric,tolbkni/fabric,simon-engledew/fabric,TarasRudnyk/fabric,likesxuqiang/fabric,jaraco/fabric,pgroudas/fabric,kmonsoor/fabric,ploxiln/fabric,askulkarni2/fabric,raimon49/fabric