docs: Add packet to index

demos/index.html

@@ -78,6 +78,9 @@
       <li>
         <h2><a href="./sankey.html">Sankey</a></h2>
       </li>
+      <li>
+        <h2><a href="./packet.html">Packet</a></h2>
+      </li>
     </ul>
   </body>
 </html>