Add custom culture to Localization Dashboard

It will be great also as a “playground”. I would like to add custom culture simply just to have something we will all work on and develop the game, and It will be most likely mix of our native langue with english, but it will be by no means The English :wink: So it will be great to have an option to create our own “delete-me-english” culture for actual development and then have the “real” en :wink: