adding README entry for winston-sns transport
adding README entry for winston-sns transport

pantheon-systems/winston,psquickitjayant/winston,auth0/winston,unlucio/winston,winstonjs/winston,modulexcite/winston,beni55/winston,s-panferov/winston,get-trucked/winston,z-10/winston,alphagov/winston,nikolas/winston,winstonjs/winston,dbmikus/winston,pphetra/winston,wancharle/winston,iizukanao/winston,thaliproject/winston,apiaryio/winston,megastef/winston,SmartNode-es/winston,aquavitae/winston,uber/winston,tobli/winston,harriha/winston,DenisGorbachev/winston,rakesh-mohanta/winston,alinex/winston,whismat/winston,paulhroth/winston,jjmleiro/winston,dustinblackman/winston