Update README url to the wiki
Update README url to the wiki

ruby-protobuf/protobuf,lookout/protobuffy,zanker/protobuf,brianstien/protobuf,zanker/protobuf,localshred/protobuf,film42/protobuf,film42/protobuf,brianstien/protobuf,quixoten/protobuf,quixoten/protobuf,localshred/protobuf,lookout/protobuffy,ruby-protobuf/protobuf