Set up a system to update translation files

[tanius]

There should be a proper system for people to comfortably create and update translations stored within the translation files in the Github repository.

That system would recognize from git commits which translations got updates in the English version and show them to translators to change the translation as well, if it needs it. It would also ask them to translate the texts for newly added translation keys. Since this is a very usual problem, there is probably a solution around that is integrated with Github and can be used by non-developers.

Anyway, this is for a later time when this might become a more complete, generic way to manage websites from within Discourse.