fix: 🩹 re-add the 404 error page

www/templates/derg_error.html

@@ -0,0 +1,19 @@
+
+{% extends "pathed_content.html" %}
+
+{% block extra_head %}
+    <link rel="stylesheet" href="/static/rrrorstyle.css">
+{% endblock %}
+
+{% block second_title %}
+<h2> (Broken) </h2>
+{% endblock %}
+
+{% block content_article %}
+    <h1 id="rrr_header"> The Dergs are confused:</h2>
+    <h2 id="rrr_code"> {{ error_code }}</h1>
+
+    <div>
+        {{ error_description|markdown_to_html }}
+    </div>
+{% endblock %}