template: Add page header to RST template

Signed-off-by: Chris Fiege <chris@tinyhost.de>

flamingo/theme/templates/page.html

@@ -3,7 +3,9 @@
 
 {% block content %}
 <div class="container" >
-    <h1>{{ content.content_title }}</h1>
+    <div class="page-header" >
+        <h1>{{ content.content_title }}</h1>
+    </div>
     {% if content.date is not none%}
     <p>
         <em>{{ content.date }}</em>