Merge pull request #229 from jupyterlab/blink1073-patch-4

Add binder link to Readme

README.md

@@ -5,6 +5,8 @@
 [![GitHub](https://img.shields.io/badge/issue_tracking-github-blue.svg)](https://github.com/jupyterlab/lumino/issues)
 [![Discourse](https://img.shields.io/badge/help_forum-discourse-blue.svg)](https://discourse.jupyter.org/c/jupyterlab)
 
+[![Binder](https://mybinder.org/badge_logo.svg)](https://mybinder.org/v2/gh/jupyterlab/lumino/master?urlpath=lab/tree/examples)
+
 Lumino is a set of JavaScript packages, written in TypeScript, that provide
 a rich toolkit of widgets, layouts, events, and data structures. These enable
 developers to construct extensible high-performance desktop-like web