replace section tags with div tags

syntactically incorrect usage, as picked up by a W3C validator

incorporealcms/templates/base.html

@@ -10,21 +10,21 @@
 <link rel="stylesheet" href="{{ url_for('static', filename=user_style) }}">
 <link rel="icon" href="{{ url_for('static', filename='img/favicon.png') }}">
 
-<section class="site-wrap">
-    <section class="styles">
+<div class="site-wrap">
+    <div class="styles">
         <a href="?style=dark">[dark]</a>
         <a href="?style=light">[light]</a>
-    </section>
-    <section class="nav">
+    </div>
+    <div class="nav">
         {% for nav in navs %}
         <a href="{{ nav.1 }}">{{ nav.0 }}</a>
         {% if not loop.last %} &raquo; {% endif %}
         {% endfor %}
-    </section>
-    <section class="content">
-    {{ content }}
-    </section>
+    </div>
+    <div class="content">
+        {{ content }}
+    </div>
     <footer>
         <i>Last modified: {{ mtime }}</i>
     </footer>
-</section>
+</div>