Add instructions on how to add authorized users

[jwmatthews]

As an administrator installing Konveyor, I need guidance of how I may add/configure additional users for Konveyor.

See a conversation in slack from a user here:
https://kubernetes.slack.com/archives/CR85S82A2/p1678870757577409

This issue involves documenting guidance of how to interact with the underlying keycloak to add additional users