Update README.md

Author: santosharron

README.md

@@ -1,6 +1,6 @@
 # 3D Mars Landing Page
 
-![Preview](https://i.imgur.com/EYGji9T.png)
+[![Preview](https://i.imgur.com/EYGji9T.png)](https://www.youtube.com/watch?v=xGpmeQ3hfXk)
 
 I used Three.js to create a great landing page in this tutorial. You'll briefly learn how to use orbit controls and dat.gui. By the end of the tutorial, you'll learn to create an awesome website like this.