Clarify that optional 'nameservers' config option must be an array
Clarify that optional 'nameservers' config option must be an array

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