Add NGVC info in introduction

Author: paulhiggs

metadata.xhtml

@@ -306,6 +306,8 @@
   <li>H.264 Scalable High Profile</li>
   <li>H.264 Stereo High Profile</li>
   <li>H.265</li>
+  <li>H.266</li>
+  <li>AVS3</li>
 </ul>
 <!-- /wp:list -->