Update instructions around exposing from a different ns

[pwright]

ATM, there's https://skupper.io/docs/cli/index.html#exposing-services-from-different-ns
However, there are now options to :

• use --enable-cluster-permissions in skupper init

• and --target-namespace in skupper expose

This feature allows Skupper to monitor deployments in other namespaces

Add doc for these options

NOTE seems to work without --enable-cluster-permissions

  skupper init
  kubectl create namespace east
  kubectl create deployment backend --image quay.io/skupper/hello-world-backend --replicas 3 --namespace east
  skupper expose deployment/backend --port 8080 --target-namespace east
  skupper service status
  kubectl create deployment frontend --image quay.io/skupper/hello-world-frontend
  kubectl expose deployment frontend --port 8080 --type LoadBalancer
  kubectl get service/frontend

[pwright]

@grs Should we replace existing doc above? or add an optional extra procedure?

Also, does user need extra privs to --enable-cluster-permissions (eg cluster-admin)

[grs]

Yes, --enable-cluster-permissions requires cluster level privileges. I think we should expand the section to show both targeting a service and a set of pods (e.g. deployment) and explain the differences between the two.