how to set up a distributed RisingWave cluster on k8s or on host.

[XuankuF]

I follow the docs to set up RisingWave on k8s, but it's only one compute/compactor pod and seem not a distributed cluster.

[xxchan]

    replicas:
      meta: 1
      frontend: 1
      compute: 1
      compactor: 1

There is a section called replicas where you can specify the number of each type of node.