Add banner.

README.md

@@ -6,6 +6,8 @@
 
 [![Awesome](https://cdn.rawgit.com/sindresorhus/awesome/d7305f38d29fed78fa85652e3a63e154dd8e8829/media/badge.svg)](https://github.com/sindresorhus/awesome) [![PRs Welcome](https://img.shields.io/badge/PRs-welcome-brightgreen.svg?style=flat-square)](http://makeapullrequest.com) [![Join the chat at https://gitter.im/hackerkid/bots](https://badges.gitter.im/hackerkid/bots.svg)](https://gitter.im/hackerkid/bots?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 
+![diff.blog](banner.jpg)
+
 Table of Contents
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