Add some error pages

html/404.html

@@ -0,0 +1,10 @@
+{% extends "base.html" %}
+
+{% block content %}
+<h2>Page Not Found</h2>
+
+<p>
+The page you are looking for was not found.
+</p>
+
+{% endblock %}

html/500.html

@@ -0,0 +1,12 @@
+{% extends "base.html" %}
+
+{% block content %}
+<h2>Server Error</h2>
+
+<p>
+The server had serious problems while serving your request. We've just sent our
+trained monkeys to fix the issue.
+</p>
+
+{% endblock %}
+