Add I2P Summer Dev branding to the top of relevant blog views

i2p2www/pages/blog/category.html

@@ -3,3 +3,10 @@
 {% block headextra %}
     <link href="{{ get_url('blog_atom', category=category) }}" type="application/atom+xml" rel="alternate" title="{% trans %}I2P Blog ATOM Feed for Category: {{ category }}{% endtrans %}" />
 {%- endblock %}
+{% block blogindextop %}
+{% if 'summer-dev' == category %}
+<div id="blog-topimg">
+  <img src="{{ url_for('static', filename='images/I2PSummerDev-Primary.svg') }}" alt="I2P Summer Dev" title="I2P Summer Dev">
+</div>
+{% endif %}
+{% endblock %}