- Removed the hint to the `-ldap` tags that where discontinnued with version 2.0.
- Increased minimum Docker version to reflect the needed version for running newer Ubuntu versions. See: https://medium.com/nttlabs/ubuntu-21-10-and-fedora-35-do-not-work-on-docker-20-10-9-1cd439d9921
- Fixed some Markdown linter errors