theme: Fix H1 on RST pages

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

flamingo/theme/templates/page.html

@@ -3,7 +3,7 @@
 
 {% block content %}
 <div class="container" >
-    <h2>{{ content.content_title }}</h2>
+    <h1>{{ content.content_title }}</h1>
     {% if content.date is not none%}
     <p>
         <em>{{ content.date }}</em>