Add obsolete notic

_includes/obsolete_notice.html

@@ -0,0 +1,8 @@
+<div class="row" style="background-color: #fffab1;">
+  <div class="col12 center">
+    <div class="container">
+      OSM2VectorTiles is no longer maintained. Please switch to the successor project <strong>
+      <a href="http://openmaptiles.org/">openmaptiles.org</a></strong>
+    </div>
+  </div>
+</div>

_layouts/page.html

@@ -7,13 +7,7 @@ layout: default
     <h1 class="white">Free Vector Tiles from OpenStreetMap</h1>
   </div>
 </div>
-<div class="row bg-gray-light">
+{% include obsolete_notice.html %}
-  <div class="col12">
-    <div class="container">
-      <strong>{{page.title}}</strong>
-    </div>
-  </div>
-</div>
 <div class="row article">
   <div class="col12">
     <div class="container padb-6">