added gif to readme

README.md

@@ -8,7 +8,7 @@
 
 Clustergrammer is a web-based tool for visualizing high-dimensional data (e.g. a matrix) as an interactive and shareable hierarchically clustered heatmap. Clustergrammer's front end ([Clustergrammer-JS](http://clustergrammer.readthedocs.io/clustergrammer_js.html#clustergrammer-js)) is built using [D3.js](https://d3js.org/) and its back-end ([Clustergrammer-PY](http://clustergrammer.readthedocs.io/clustergrammer_py.html#clustergrammer-py)) is built using Python. Clustergrammer produces highly interactive visualizations that enable intuitive exploration of high-dimensional data and has several biology-specific features (e.g. enrichment analysis, see [Biology-Specific Features](http://clustergrammer.readthedocs.io/biology_specific_features.html#biology-specific-features)) to facilitate the exploration of gene-level biological data. Click the screenshot below to view an interactive tutorial:
 
-[![demo_screenshot](img/demo_screenshot.png "demo_screenshot.png")](http://maayanlab.github.io/clustergrammer/scrolling_tour)
+[![demo_screenshot](img/demo_high-fr.gif "demo_high-fr.gif")](http://maayanlab.github.io/clustergrammer/scrolling_tour)
 
 Clustergrammer's interacive features include:
 - [Zooming and Panning](http://clustergrammer.readthedocs.io/interacting_with_viz.html#zooming-and-panning)