Deal with updated translations

[rolandgeider]

Think about how to handle updated translation files. At the moment, the .po files are merged by the weblate bot, but to use them they have to be compiled to .mo files. To avoid filling the repository history with binary garbage, this process hapens only once in a while or during releases.

For docker this could happen during build, or we could also compile this when boostraping

-> see how to avoid merge conflicts when the user pulls from the repo?