refactor(body) moved body from layout to separate pages

this allows us to wrap the body with custom divs for each page if necessary

src/templates/slides.html

@@ -22,4 +22,9 @@
         link.href = window.location.search.match( /print-pdf/gi ) ? 'static/css/print/pdf.css' : 'static/css/print/paper.css';
         document.getElementsByTagName( 'head' )[0].appendChild( link );
     </script>
+{% endblock %}
+
+{% block body %}
+    {{ super ()}}
+    {{ body | safe }}
 {% endblock %}