Translator credits added manually based on Weblate git log.
Adds Catalan, Danish and Norwegian Bokmål initial translations.
Those were initially translations for the master branch, merged
against the 2.1 template.
It is simpler to sync everything from Weblate and to maybe delete incomplete translations
before building release binaries, than to try to cherry-pick changes (which leads to painful
merge conflicts on Weblate's git repo
