Update custom-search.cn.html.md
Merge pull request #21 from hemslo/develop

Add image schema to crawler
Add install doc
Update install.cn.html.md
Update overview.cn.html.md
Merge pull request #22 from wendycan/master

Add install doc
doc for ruby
update ruby doc
Merge pull request #23 from fellesy/master

doc for ruby
fix crawler bug
add wx group
update img style
fix qrcode style
update cdn link
fix qrcode bug
fix button style
update docs
update python, ruby library
fix python doc error
update overview of libs