I meant the language for the app in the store.
But there is a plugin for Visual Studio for easy localization. It creates a new folder in the root of the exported project with files in it. But you cant access them via AJAX if they are not in the subfolder of the app/game? Maybe it works if you copy/move them there after you are done with it.
Can I just enter multiple language codes in the app manifest in Visual Studio? I will need to try this tomorrow (so the shop shows multiple supported languages if I just hardcode them in for now).