[docs] OpenShift 3 quickstart instructions for having multiple deployments doesn't do anything

[amisevsk]

Is your enhancement related to a problem? Please describe.

The section "Having multiple Che deployments" in the OpenShift 3 quickstart doesn't have enough detail to make sense; running the provided command simply prints that nothing happened:

$ oc patch clusterrolebinding che-operator \
    --type='json' \
    -p '[{"op": "add", "path": "/subjects/0", "value": {"kind":"ServiceAccount", "namespace": "chectl-test", "name": "che-operator"} }]'
clusterrolebinding.authorization.openshift.io/che-operator not patched

The original deploy command is

chectl server:start -n <namespace> -p openshift

as suggested in the doc.

Likely this section should just be removed, as Che installs will only support a single namespace in the near future (and so multiple deployments won't make sense).

Additional Info

Originally encountered while using downstream crwctl/2.3.0-GA-redhat.abf3efd linux-x64 node-v10.19.0, reproduced it with chectl/0.0.20200820-next.290685f linux-x64 node-v10.22.0