Add publication to poll cards.

polls/templates/polls/index.html

@@ -8,6 +8,7 @@
             {% for question in latest_question_list %}
                 <div class="poll-card">
                     <h3><a href="{% url 'polls:detail' question.id %}">{{ question.question_text }}</a></h3>
+                    <p class="publication-date">Published on: {{ question.pub_date|date:"F j, Y" }}</p>
                 </div>
             {% endfor %}
         {% else %}