Add Linux Foundation copyright language

Signed-off-by: lucperkins <[email protected]>

Author: lucperkins

layouts/partials/footer.html

@@ -7,6 +7,12 @@
         © {{ $year }} The Update Framework authors | Documentation Distributed under CC-BY-4.0
       </p>
 
+      <p class="has-text-weight-bold">
+        &copy; {{ $year }} 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</a> page. 
+      </p>
+
+      <hr />
+
       {{ $copy }}
     </div>   
   </div>