readme: add explanation
readme: add explanation
mqliang/etcd,etcd-io/etcd,li-ang/etcd,li-ang/etcd,dannysauer/etcd,coreos/etcd,ajityagaty/etcd,etcd-io/etcd,ajityagaty/etcd,cockroachdb/etcd,mkumatag/etcd,cockroachdb/etcd,rnaveiras/etcd,mkumatag/etcd,dannysauer/etcd,coreos/etcd,etcd-io/etcd,ajityagaty/etcd,gyuho/etcd,mkumatag/etcd,mqliang/etcd,rnaveiras/etcd,rnaveiras/etcd,mqliang/etcd,gyuho/etcd