Update the readme and other documentation

Description

Since there were quite a few changes the readme file(s) and documentation might be outdated and require some attention. Let's collect some issues for now and then do the update at some point.

• Clab? Example requires update, maybe list or link to the available images in the clab
• Rbac?
• API?
• CLI?
• Info about additional images (db, rabbit, etc.), maybe link to example config