* Add general hints that this example only shows how the components
work together and that a GNU/Linux admin should be consulted for
a secure setup.
* Adjust the scripts that setup a testing instance to use better
permissions as good example.
* Add a section about security considerations.
* Add an OpenPGP test keypair.
* Move script parts of documentation into script, so they can be used on a fresh Ubuntu 20.04 system
for within a github action to setup a csaf_provider and upload documents to it for an integration test.
* Use dineshsonachalam/markdown-autodocs in github action to automatically
insert lines from the scripts into the docs.
Co-authored-by: Bernhard Reiter <bernhard@intevation.de>
