:art: Add a demonstration gif

README.md

@@ -8,6 +8,8 @@ This plugin is small, stable and adaptable.
 
 ## Features
 
+![godot slide animated demo](doc/wait-for-gd-example.gif)
+
 ### A slide is a scene
 
 Leverage the Godot scene system by providing a custom Slide node to use as root for your slide scene. Then you are free to add anything in your slide scene. Don't forget to include it as a child of your Show node in your main scene.