Need clarifications on user names

The server-add command requires a username and a server-add-username, but this document doesn't clearly state the RBAC roles for each. It simply says that username needs permission to execute the command and server-add-username should a user with appropriate credentials to modify the cluster topology. Furthermore, the single example shown in this document simply uses the default Administrator credentials for both.

Please update the document mentioning lowest RBAC roles required for each user and provide a better example.

The document for server-readd command also has the same issues. Please update that as well.

Reporter: Nirvair Singh
E-mail: nirvair.singh@couchbase.com