add Chinese translation

[rqnj]

new translation: Chinese (simplified)

[Twipped]

Thank you very much! I'll work on getting this linked into the site. It's the first complete translation that I've received. At least, I assume it's complete, since I can't read it 😅

I had to make a modification to the PR because image names can't actually have hyphens in them. It's a limitation of the engine.