[i18n]: Add zh-CN README, delete duplicate content in original README

[Octopus058]

Type of i18n contribution

Update existing translations

Language

Simplified Chinese

Description

I add a Simplified Chinese Version (README.zh-cn.md), also delete duplicate content in README.md.

There r some duplicate paragraphs in the original README, so i delete them and slightly modified the indentation of the first line (If it's not proper then restore is ok). Also, I think there's nothing better than adding a zh-CN README!

Additional context

Think highly of you, hope your browser can achieve great success sincerely xD

Moreover, I have submitted Follow to HelloGithub Program!

Code of Conduct

• [X] I agree to follow this project's Code of Conduct