Add sources display to question detail view for better reference tracking

sbas/templates/sbas/question_detail.html

@@ -34,6 +34,17 @@
                 Best answer: {{ question.best_answer }} ({{question.get_correct_answer_stripped}})
             </div>
         {% endautoescape %}
+        <div>
+            Sources:
+            {% if question.sources %}
+                <ul>
+                    {% for source in question.sources %}
+                        <li>{{ source }}</li>
+                    {% endfor %}
+                </ul>
+            {% else %}
+                None
+            {% endif %}
         <div>
             Examinations: {% for exam in question.exams.all %}
                 <a href="{% url 'sbas:exam_overview' pk=exam.pk %}">{{ exam }}</a>