Merge pull request #1 from walzer/master

Doc "Why use cocos2d-html5 for game development" is done.
Merge pull request #2 from walzer/master

adjust the folder structure, use en.md, zh.md, ko.md instead of divide 1...
Merge pull request #3 from walzer/master

fixed #2987, create a new structure for documents.
add new articles
add read me and rename tutorials name
modify some minor errors
Merge pull request #4 from andyque/new_parkour

fixed #3270, move old tutorials repository to cocos-doc
rename some folders
fixed #3270, rename some folder names
Merge branch 'master' of github.com:andyque/cocos-docs
Merge pull request #6 from andyque/master

fixed #3270, move old tutorials repository to cocos-doc
new layer structure picture, fix  grammar error.
Merge pull request #7 from u0u0/master

new layer structure picture, fix  grammar error.