Making OpenWrt releases

20.xx
High-level release process
How to create a major release
How to create a service release
How to prepare buildbot for major release
Prepare Nitrokey 3A Mini for build artifact signing
Release goals for 19.07.4
Release goals for 21.XX
Release goals for 22.03
Release goals for 23.xx
Roadmap and Release Goals for 21.02
Update package lists
Update wikidata