Section Number and Name:
Operator-SDK documentation. Related to Helm-operators

Describe the issue:
The following behavior in helm operator project needs to be mentioned in documentation:
While scaffolding a new project, the helm operator scaffolder tries to use the cluster config for the best information. The permissions scaffolded in roles/rbac.yaml is based on whether the cluster config can be found or not.

While scaffolding a helm based project, `operator-sdk create api` needs to have a KUBECONFIG present. If not, users will have to add the required permissions for serviceaccount (in rbac/roles.yaml) manually.

For example:
```

• apiGroups:
• demo.my.domain
  resources:
• nginxes
• nginxes/status
• nginxes/finalizers
  verbs:
• create
• delete
• get
• list
• patch
• update
• watch
• verbs:
• "*"
  apiGroups:
• ""
  resources:
• "serviceaccounts"
• "services"
• verbs:
• "*"
  apiGroups:
• "apps"
  resources:
• "deployments"

```

Additional information:
The OCP documentation should point out the behavior of helm operator scaffolder to reduce confusions related to scaffolding of roles.yaml in the project.

cc: Alex Dellapenta (alexd@redhat.com)