Update index.html

Author: JC-ProgJava

SmartEditor HTML/index.html

@@ -159,7 +159,7 @@ <h1 id="Heading">SmartEditor, a lightweight yet powerful texteditor.</h1>
         <a style="margin: unset;" href="#Download"><img style="max-width: 20%; max-height: 20%;"src="notepad.png"></a>
         <h2 style="text-align: center; font-size: 30px;">Built using <em>Java</em></h2>
         <video autoplay loop>
-          <source src="Demo.mov" type="video/mov">
+          <source src="Demo.mp4" type="video/mp4">
         </video>
         <div>
         <h2 id="Features">SmartEditor Features</h2>