cleanup README
cleanup README

netf/skydns,yonglehou/skydns,zhang0137/skydns,tonicbupt/skydns,AdoHe/skydns,no2key/skydns,hw-qiaolei/skydns,vinhhrv/skydns,loveshell/skydns,nicescale/skydns,smarterclayton/skydns,skynetservices/skydns,erimatnor/skydns-kubernetes,zvelo/zvelo-skydns,ZeaLoVe/skydns,andrewrothstein/skydns,tuannvm/skydns,weekface/skydns