docs(tools/cbmc): add application note on CBMC

Change-Id: I4acd1e0e75a144b379c99e76a852fe1bddc44bef
Signed-off-by: Mate Toth-Pal <mate.toth-pal@arm.com>
diff --git a/docs/index.rst b/docs/index.rst
index b7a0415..9da6cd6 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -42,6 +42,13 @@
             </a>
             <p>Security.</p>
         </li>
+        <li class="grid-item">
+            <a href="resources/index.html">
+               <img alt="" src="_static/images/rmm-documentation.png"/>
+               <h2>Resources</h2>
+            </a>
+            <p>Resources.</p>
+        </li>
     </ul>
 
 .. toctree::
@@ -54,4 +61,5 @@
    process/index
    design/index
    security/index
+   resources/index
    glossary