Maybe you forgot to set up TranslatableText?

Ah, I probably found it: in ru_ru.json, line 30 is not terminated with a comma. That makes it malformed json, and that's likely why it doesn't get loaded. I will push an update to fix that tomorrow.

Yep, that was it. New version pushed :)

That is odd. All translatable text gets generated by AutoConfig, which uses TranslatableText, and all English text is taken from the translation file. So it should work just fine... but I can see that it doesn't.