🌐(i18n) Languages configurable per instances

[AntoLC]

Feature request

We should be able to configure the languages that we want per instances.

See:

docs/src/backend/impress/settings.py

Lines 236 to 245 in f8a40cf

	LANGUAGES = values.SingleNestedTupleValue(
	(
	("en-us", "English"),
	("fr-fr", "Français"),
	("de-de", "Deutsch"),
	("nl-nl", "Nederlands"),
	("es-es", "Spanish"),
	("cn-cn", "Chinese"),
	)
	)

[rvveber]

Is there a good reason for this?

[AntoLC]

On our instances we want to focus on the European languages, but Chinese by example should be selectable as well on your instance if you want it.

[rvveber]

Hm, what if a chinese guest is invited to a public document?
Or what if someone that natively speaks chinese starts to work at XY?

[rvveber]

I'd need to work on this next