Update create-a-voice-virtual-assistant.mdx

Author: asiqurrahman

projects/create-a-voice-virtual-assistant/create-a-voice-virtual-assistant.mdx

@@ -52,7 +52,7 @@ Here is a sneak peek of the final assistant in action:
 
 <p align="center">
     <video width="1280" height="480" controls>
-        <source src="media/demo.mp4" type="video/mp4">
+        <source src="media/demo.mp4" type="video/mp4" />
     </video>
 </p>