Document the RBAC for the postgres-operator #256
Description
In particular:
- provide a step-by-step quickstart how to configure the operator using RBAC
- include Patroni RBAC into the operator. Since the definition itself is in the Patron project, add the disclaimer into the documentation about it possibly not being most up-to-date. Alternatively, just use the kubectl with the https path to the Patroni manifest (however, it has more than just RBAC at the moment).
We also need to possibly document the usage of PlatformCredentialsSet.