Define release process

A list of things that need to be done when doing a new release:

- check if all templates are in line with the curriculum
- check diagrams, screenshots
- check accessibility (contrast for images, alt text, abbreviations, etc.)
- check reference file is in line with all used references (also extract all links into links.md)

Start with the release checklist in this issue and inspect the repository's templates, diagrams, screenshots, accessibility details, reference file, and links.md. Compare those materials with the curriculum and references; done means the release checks are documented and each listed item has been reviewed.

Written by the indexing model from the issue text.