Add to index.html

Author: mattam82

src/index.html

@@ -174,6 +174,12 @@ <h2 id=eq-tut>Equations Tutorials</h2>
         and
         <a href="Tutorial_Equations_wf.v">source code</a>
       </li>
+      <li>
+        Indexed inductive types and tactics:
+        <a href="Tutorial_Equations_indexed.html">interactive version</a>
+        and
+        <a href="Tutorial_Equations_indexed.v">source code</a>
+      </li>
     </ul>
   </body>
 </html>