Update README.md
add folder group
Merge branch 'mergecocos3.0' into xiaoMergecocos3.0
Merge pull request #19 from dabingnn/xiaoMergecocos3.0

Xiao mergecocos3.0
Merge pull request #20 from houguohua/android

Update README.md
Merge branch 'mergecocos3.0' of github.com:cocos2d/cocos3d-x into mergecocos3.0

Conflicts:
	README.md