There seemed to be a bit of confusion over what languages the mod supports.
The mod uses the same language file format as the base game, and comes with the same set of languages (sometimes slightly out of date). Any custom translation can also be loaded into the mod the same way as with the base game.
The store page had now been updated to show the supported languages correctly (previously showed just English).
A few missing CBT-specific snippets of text (like the initial menu) will be localized in upcoming update