Updates header with both new pages

Author: charlottebrf

_includes/header.html

@@ -13,6 +13,12 @@
     <li class="nav-item">
       <a class="nav-link" href="open_source_accelerator.html">Open source accelerator</a>
     </li>
+    <li class="nav-item">
+      <a class="nav-link" href="ministers_under_the_influence.html">Ministers Under The Influence</a>
+    </li>
+    <li class="nav-item">
+      <a class="nav-link" href="what_the_fact.html">What The Fact</a>
+    </li>
   </ul>
 </nav>