Add Mandarin templates

The templates were provided by [[User:白布飘扬]] [1] at
[[Wikidata:Wikidata Lexeme Forms/Mandarin]] [2] – thank you!

[1]: https://www.wikidata.org/wiki/User:%E7%99%BD%E5%B8%83%E9%A3%98%E6%89%AC
[2]: https://www.wikidata.org/wiki/Wikidata:Wikidata_Lexeme_Forms/Mandarin