Instruction errors in `Run etcd clusters inside containers`

[Yiyiyimu]

In https://etcd.io/docs/v3.4/op-guide/container/#running-a-3-node-etcd-cluster-1

1. latest tag of gcr.io/etcd-development/etcd is 3.3.12 and quay.io even more outdated that uploaded three years ago. I guess the authority is on your side so if would be great if you could update the latest tag to the correct version. Ref: gcloud and quay

2. all three etcd nodes in docker have the same name etcd so the cluster could not be built. Might change to name to ${THIS_NAME}

   docker run \
   -p 2379:2379 \
   -p 2380:2380 \
   --volume=${DATA_DIR}:/etcd-data \
   --name etcd ${REGISTRY}:${ETCD_VERSION} \
   ...

3. use detached mode when docker run, or the rest commands could not be accessed.

[patrocinio]

The same issue applies to the "Running a single node etcd" section in v3.5 documentation