Add link to jupyterlab source

README.md

@@ -2,7 +2,7 @@ Jupyter JS Plugins
 ==================
 
 Plugins for JupyterLab.  The default set of [phosphide](https://github.com/phosphorjs/phosphide) 
-plugins used to create JupyterLab.
+plugins used to create [JupyterLab](https://github.com/jupyter/notebook/tree/master/notebook/lab).
 
 ![JupyterLab Demo](jupyter-plugins-demo.gif)