Add labs option to upload translation files

So, right now, I’m using Ghost(Pro) Starter with an official theme, and if I want to translate the official theme I can’t upload it cause I need to upgrade to Creator to be able to use custom themes, but all I’ve done was adding translations to an official theme.

It would be nice to be able to upload translation file/s in labs.

This way you don’t have to change the theme if you want to change particular labels.