Add Chinese Translation

[PikAsriel]

Thank you.

[Nrosa01]

Hi! I really appreciate this but sadly I can't merge it.

There are more files that must be translated for this to work, like the questions json, or the nature descriptions. Also notice the name of the other folders, I only take the second part, so it would only be hans and hant, without zh-.

Once that's done I'll add the language to the utils.js languageSet and I'll test it.

[PikAsriel]

Maybe I will host the Chinese translation on my GitHub website instead for me to be easier to update the translation. I will provide credit at the same time.