Duplicated simplified-chinese translated README

Hi, I noticed that there are two README translations for Simplified Chinese, they are README_zh-CN.md and README_zh.md.
And I checked the difference between them, only a few paragraphs are in different words but in the same meaning.

I think we can merge them into one file.

If this is allowed, I would like to make a pull request.

I noticed this because of the question mark after the relative link. 😆

project-layout/README.md

Line 8 in 762f59e

* [简体中文](README_zh-CN.md) - ???

I had already checked the previous PR, this might be related to #188 and #151.