Update README.md
Update README.md
Update README.md
Update README.md
Update README.md
Update README.md
Update README.md
Update README.md

As per review comments in https://github.com/es6rocks/es6rocks.github.io/commit/7db5fae39b1675aa3456233f81972211414a39c3
Update contributing guide

Add branching, fix some missing steps (can't checkout to `src` right after cloning).
Merge pull request #22 from es6rocks/contributing

Update contributing guide
Readme: small grammar fix
Merge pull request #1 from es6rocks/master

更新作者合并