Docs: Add some sidebar links

Resources
- Lit lifecycle
Tutorials
- Converting to webcomponent
- Automatic testing

doc/etemplate2/_includes/sidebar.njk

@@ -16,6 +16,7 @@
       <li><a href="https://help.egroupware.org">Community</a></li>
       <li><a href="https://www.egroupware.org/en/professional-support">Help &amp; Support</a></li>
       <li><a href="https://github.com/EGroupware/egroupware/releases">Changelog</a></li>
+      <li><a href="https://lit.dev/docs/components/lifecycle/">Lit Lifecycle</a></li>
     </ul>
   </li>
   <li>
@@ -39,6 +40,8 @@
     <h2>Tutorials</h2>
     <ul>
 	  <li><a href="/tutorials/creating-a-widget">Creating a widget</a></li>
+	  <li><a href="/tutorials/converting-to-webcomponents.md">Converting to WebComponent</a></li>
+	  <li><a href="/tutorials/automatic-testing.md">Automatic testing</a></li>
       <li><a href="/tutorials/integrating-with-egw">Integrating with EGroupware</a></li>
       <li><a href="/tutorials/link-system">Implementing the linking system</a></li>
     </ul>