docs: adding rs api docs

Change-Id: Ib56ee177439e9c124d0ac4053ed4173f8a4be1aa
diff --git a/docs/html/guide/guide_toc.cs b/docs/html/guide/guide_toc.cs
index a9c4d30..3b1642f 100644
--- a/docs/html/guide/guide_toc.cs
+++ b/docs/html/guide/guide_toc.cs
@@ -282,6 +282,10 @@
                 <span class="en">Compute</span>
               </a>
           </li>
+          <li><a href="<?cs var:toroot ?>guide/topics/renderscript/reference.html">
+                <span class="en">Runtime API Reference</span>
+              </a>
+          </li>
         </ul>
       </li>