Docs: Add Debugging ART garbage collection

Bug: 22562924
Change-Id: Ib8ea621b1cf02a056f19c36f4ffd455c985abc85
diff --git a/src/devices/devices_toc.cs b/src/devices/devices_toc.cs
index 82a4750..09c6396 100644
--- a/src/devices/devices_toc.cs
+++ b/src/devices/devices_toc.cs
@@ -182,6 +182,7 @@
           <li><a href="<?cs var:toroot ?>devices/tech/dalvik/instruction-formats.html">Instruction Formats</a></li>
           <li><a href="<?cs var:toroot ?>devices/tech/dalvik/constraints.html">Constraints</a></li>
           <li><a href="<?cs var:toroot ?>devices/tech/dalvik/configure.html">Configuration</a></li>
+          <li><a href="<?cs var:toroot ?>devices/tech/dalvik/gc-debug.html">Garbage Collection</a></li>
         </ul>
       </li>