File summary all code

I wrote a summary file to show all code in one page.

![hello-world-summary](https://cloud.githubusercontent.com/assets/961856/3633773/47135964-0ef8-11e4-9a4a-d7d5817eeb9c.jpg)

# Implementation

* Repository related code and content are got using Github APIs.
* Ajax requests are done by jQuery.
* Page style is using Bootstrap.

# Conventions

* Top level folder is language group. Should be any word except `#`.
* Second level folder should be language hello-world code.

**Notice:** You should not refresh frequently because of Github rate limitations.