Add links to the sidebar nav

_layouts/default.html

@@ -156,7 +156,7 @@ layout: compress
             <strong>Navigation</strong>
             <li><a href="/">Home</a></li>
             {% for i in site.urls %}
-              <li><a class="about" href="{{ i.url }}">{{ i.text }}</a></li>
+              <li><a class="about" href="{{ i.url }}"{% if i.target_blank %} target="_blank"{% endif %}>{{ i.text }}</a></li>
             {% endfor %}
           </ul>
           <hr>