Update index.mdx

Author: eigenvivek

src/pages/index.mdx

@@ -20,7 +20,7 @@ import IframeGrid from "../components/IframeGrid.astro";
 import dogsDiffc from "../assets/dogs-diffc.png"
 import dogsTrue from "../assets/dogs-true.png"
 
-import teaser from "../assets/teaser.mov";
+import teaser from "../assets/teaser.mp4";
 import polyexplain from "../assets/polyexplain.png"
 
 import CodeBlock from "../components/CodeBlock.astro";