docs: Adding research papers section to ndnSIM website
diff --git a/docs/ns3_html_theme/layout.html b/docs/ns3_html_theme/layout.html
index f41fa31..b401d9a 100644
--- a/docs/ns3_html_theme/layout.html
+++ b/docs/ns3_html_theme/layout.html
@@ -54,8 +54,11 @@
 {% endblock %}
 
 {% block rootrellink %}
-    <li style="background: none"><a href="{{ theme_homepage }}">{{ theme_projectname }}</a><span class="navelem">&nbsp;</span></li>
-    <li style="background: none"><a href="{{ theme_apidocsurl }}">{{ theme_apidocs }}</a><span class="">&nbsp;</span></li>
+    <li style="background: none"><a href="index.html">{{ theme_projectname }}</a><span class="navelem">&nbsp;</span></li>
+    <li style="background: none"><a href="doxygen/annotated.html">{{ theme_apidocs }}</a><span class="">&nbsp;</span></li>
+    <li style="background: none"><span class="">&nbsp;&nbsp;&nbsp;&nbsp;</span></li>
+    <li style="background: none"><a href="getting-started.html">Getting started</a><span class="">&nbsp;</span></li>
+    <li style="background: none"><a href="ndnsim-research-papers.html">Research papers</a><span class="">&nbsp;</span></li>
 {#
     {{ super() }}
 #}