Add copyright footer to fix cds-hooks#475

Signed-off-by: Joe Kutner <jpkutner@gmail.com>

Author: jkutner

themes/buildpacks/layouts/partials/footer.html

@@ -17,5 +17,10 @@
         {{ end }}
       </ul>
     </div>
+    <div class="container sub-footer">
+      <ul>
+        <li><p>Copyright © 2022 The Linux Foundation ®. All rights reserved. The Linux Foundation has registered trademarks and uses trademarks. For a list of trademarks of The Linux Foundation, please see our <a href="(https://www.linuxfoundation.org/trademark-usage">Trademark Usage page</a></p></li>
+      </ul>
+    </div>
   </div>
 </footer>