add room list to orga view

pretalx_lower_thirds/templates/pretalx_lower_thirds/orga.html

@@ -21,6 +21,16 @@
             Use <code>{EVENT_SLUG}</code> to get the event slug.
             Use <code>{TALK_SLUG}</code> to get the talk slug.
         </p>
+
+        {% if request.event.rooms %}
+        <h3>{% trans "room list" %}</h3>
+        <ul>
+        {% for room in request.event.rooms.all %}
+            <li><a href="{% url 'plugins:pretalx_lower_thirds:lowerthirds' request.event %}#{{ room.name }}">{{ room.name }}</a></li>
+        {% endfor %}
+        </ul>
+        {% endif %}
+
         <div class="submit-group panel">
             <span></span>
             <span class="d-flex flex-row-reverse">