Improve documentation

[buep]

The documentation, taking offset in the README are very elaborate and many details. I think to many details and to elaborate.

When our internal users, and customers implement PAC we often get a lots of questions about configuration, how to get it running. I consider this to be due to our documentation.

I think the approach should be collect all the questions and discussions around PAC usage, and extract some information what is missing.
Then we want to simplify the documentation README to b very simple, but point even more to extended section in other readmes.