Browser languages (edit)
http://www.lingoes.net/en/translator/langcode.htm
https://gist.github.com/wpsmith/7604842
How to: Client-side language detection
https://gu.illau.me/posts/the-problem-of-user-language-lists-in-javascript/
https://makandracards.com/makandra/40217-how-to-client-side-language-detection
Best solution: SubString(0,2)
