* Update zh-CN translations.
* Update doorkeeper.zh-CN.yml
* Follow @Artoria2e5 's change advices.
* forget mail for text format ......
* fix some changes
* mail's html version ......
* https://github.com/tootsuite/mastodon/pull/2699#pullrequestreview-35982283
* a space.....
* delete some unused keys
