Add list of supported versions to docs

Version Control Information

Source branch: feature/supported-releases Target branch: devel

Commits:

* Add list of supported versions to docs

  The versions are parsed from the changelog and then evaluated by
  the given policies of the project.
  The newest supported patch version of each minor version is then listed 
  in the docs.
  If available, an EOL date is added.

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Description

This MR explicitly adds a list of supported versions to the docs.

Superseded-by: meta!2 (merged)

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Merge Prerequisites

• MR title (and description) are descriptive
• Code is readable and syntactically correct
• Code is understandable
• Documentation has been updated, if necessary
• Commit messages look good
• Release note file in RST format added in latest commit

As a developer: please do not tick these boxes yourself. As a reviewer: please get yourself a hot cold beverage.