Prevent troggle adding the menu if there is one in the file

Add a Docker compose file to bring up a dev troggle easily
Various PEP improvments

templates/core/expedition_list.html

@@ -0,0 +1,14 @@
+{% extends "base.html" %}
+{% load wiki_markup %}
+{% load link %}
+
+{% block content %}
+<h1>Expeditions</h1>
+<ul>
+{% for expedition in object_list %}
+    <li>{{ expedition.year }} - <a href="{{ expedition.get_absolute_url }}">{{ expedition.name }}</a></li>
+{% empty %}
+    <li>No articles yet.</li>
+{% endfor %}
+</ul>
+{% endblock %}

templates/flatpage.html

@@ -3,5 +3,13 @@
 {% block bodyattrs %}{% if homepage %} id="homepage"{% endif %}{% endblock %}
 {% block body %}
 {{ body|safe }}
-{% if homepage %}{% if editable %}<a href="{% url "editflatpage" path %}">Edit</a>{% endif %}{%else %}{% include "menu.html" %}{% endif %}
+{% if homepage %}
+  {% if editable %}
+    <a href="{% url "editflatpage" path %}">Edit</a>
+  {% endif %}
+  {%else %}
+    {% if not has_menu %}
+      {% include "menu.html" %}
+    {% endif %}
+  {% endif %}
 {% endblock %}