add plan in todo readme

backend.py

@@ -61,6 +61,7 @@ def create_app():
     app.add_route('/demo/add', event_form)  # Handle event submission form
     app.add_route('/demo/by-what', demo, suffix='by_what')  # Handle events by type page
     app.add_route('/demo/map-by-what', demo, suffix='map_by_what')  # Handle map by event type page
+    app.add_route('/demo/edit/{id}', demo, suffix='edit')  # Handle event editing page
     
     logger.success("Application initialized successfully")
     return app