Add error pages

templates/404.html

@@ -0,0 +1,13 @@
+{% extends "base.html" %}
+
+{% load i18n %}
+
+{% block content %}
+    <h1>{% trans "Page not found" %}</h1>
+    {% blocktrans %}The requested path <code>{{ request_path }}</code> was not found on the server.{% endblocktrans %}
+    {% if exception != "Resolver404" %}
+        <div>
+            {% trans "Exception message:" %} {{ exception }}
+        </div>
+    {% endif %}
+{% endblock %}