Updating Chinese (Simplified) translations (#5508)
* i18n: (zh-CN) fix punctuations and spaces
Spaces are fixed according to https://github.com/sparanoid/chinese-copywriting-guidelines
* i18n: (zh-CN) fix punctuation
* i18n: (zh-CN) Adapt official translation of Discourse Privacy Policy from GitHub, with minor fixes
https://github.com/discourse/discourse/blob/master/config/locales/server.zh_CN.yml#L2677