完成旧版翻译合并100%
review get-the-codes
up to date
translate description,add keywords
add CONTRIBUTING-ZH
finished CONTRIBUTING-ZH
finished CONTRIBUTING-ZH
finished CONTRIBUTING-ZH
finished Understanding Polymer
finished Using elements
finished The platform
finished Custom elements 101
remove GAE.log
finished Reusable elements
core-ajax元素翻译

Signed-off-by: 顾翔 <c0710204@gmail.com>
修正少量过度翻译

Signed-off-by: 顾翔 <c0710204@gmail.com>
task
Merge branch 'master' of github.com:c0710204/docs