Add gif for selectfolders in README

README.md

@@ -12,6 +12,10 @@ python3 setup.py install
 
 ## List of nbUI
 
-### SelectFolder: A simple folders selection
+### SelectFolders: A simple folders selection
 
-Allow users to select one or multiple folders [demo](./demo_selectfolders.ipynb)
+Allow users to select one or multiple folders. Navigation in file system follow [Unix syntax](https://en.wikipedia.org/wiki/Path_(computing)) with autocompletion.
+[demo](./demo_selectfolders.ipynb) 
+[in nbviewver](https://nbviewer.jupyter.org/urls/gitlab.com/discosoleil/nbui/-/raw/master/demo_selectfolders.ipynb)
+
+![selectfolders_screenshot](./docs/images/selectfolders.gif)