* add zh-cn readme
* edit readme
* Round 1 of edits
- Mandarin translation of QMK products is off, best to use the English name.
- Fix some terminology and grammar.
* trying re-translating the first paragraph
* add fallback langurages
* Create LANGS.md
* Rename docs/zh-cn/README.md to docs/zh/README.md
* Update LANGS.md
* Update index.html
* Delete README.md
* add sidebar for zh
