improve layer documentation with full example

[bierett]

I have updated the documentation for layer configuration with a full example.

[bierett]

I see, there are more than my commit. I will check that ASAP.

[tfr42]

Thank you for your contribution. Please see the following remarks from the TMC members:

• Please provide a clean commit with less commits.
• Check if you can use cherry pick merge or just copy it into a new PR.

However, we found that it is not ready yet for inclusion. The TMC would be happy if can find the time to address these shortcomings.

[bierett]

Instead rebase I have delete my remote branch. So I have created a new Pull Request. See #549.