add main region instead of div for WAI

templates/index.html

@@ -3,7 +3,7 @@
 {% block custombefore %}
 {% include "custombefore.html" %}
 {% endblock %}
-<div class="crunkcolumns">
+<main class="crunkcolumns">
   {% block customcolumn %}
   {% include "customcolumn.html" %}
   {% endblock %}
@@ -20,7 +20,7 @@
     </div>
   </div>
   {% endfor%}
-</div>
+</main>
 {% block customafter %}
 {% include "customafter.html" %}
 {% endblock %}