modified README

Author: emmanuelle

README.md

@@ -6,8 +6,8 @@ annotating images, as well as utility functions for using such
 annotations for various image processing tasks. 
 
 Try out the 
-[demo app for object segmentation](http://dash-canvas.herokuapp.com/app1) or the
-[demo app for manual correction of segmentation](https://dash-canvas.herokuapp.com/app2).
+[gallery of examples](https://dash-canvas.plotly.host/Portal/) and [read
+the doc](https://dash.plot.ly/canvas) to learn how to use dash-canvas.
 
 <p style="text-align:center;"><img src="doc/segmentation.gif" alt="Segmentation app" width="65%"></p>