add custom 404 page

app/__init__.py

@@ -1,4 +1,4 @@
-from flask import Flask, session, request
+from flask import Flask, session, request, render_template
 from dotenv import load_dotenv
 from .models import Avatars, Users, PostHistory, Posts, MOTD
 from .auth import digest
@@ -227,7 +227,7 @@ def create_app():
         elif request.path.startswith('/api/'):
             return {'error': 'not found'}, e.code
         else:
-            return e
+            return render_template('common/404.html'), e.code
 
     # this only happens at build time but
     # build time is when updates are done anyway