Update enterprise_sidebar.html

Author: nrios14

_includes/enterprise_sidebar.html

@@ -46,6 +46,9 @@ <h3>Enterprise 2.x Archive</h3>
         <li><a href="/user/enterprise/setting-up-travis-ci-enterprise/">Setting up Travis CI Enterprise 2.x</a> </li>
         <li><a href="/user/enterprise/upgrading/">Upgrading Travis CI Enterprise 2.x</a></li>
         <li><a href="/user/enterprise/tcie-3.x-migrating-db-from-2.x-to-3.x/">Migrating Database from 2.2.6+ to 3.x</a></li>
+        <li><a href="/user/enterprise/operations-manual-tcie-2.x/">Operations Manual for 2.x</a></li>
+        <li><a href="/user/enterprise/high-availability-tcie-2.x/">High Availability for 2.x</a></li>
+        <li><a href="/user/enterprise/platform-tips-tcie-2.x/">Platform Administration Tips for 2.x</a></li>
       </ul>
 
       <h3>Travis CI Docs</h3>