Hi there! So the language addon is actually just a font that includes characters for the language, and in then in the case of a Chinese or Japanese font it changes from word count to character count. I'm honestly not sure how I would make a tutorial on how to make a new language addon because it would really depend on the language. In the future I am hoping to localize the software and get rid of the language addons (since they won't be needed), but since it's just me I'm not sure when I'll be able to complete that. I will try to make a general addon tutorial soon though!