add code snippet for city hub

src/components/editor-snippets.ts

@@ -25,6 +25,13 @@ ace.define('ace/snippets/python', ['require', 'exports', 'module'], function (
 	from pybricks.tools import wait
 
 	hub = CPlusHub()
+snippet cityhub
+		from pybricks.hubs import CityHub
+		from pybricks.pupdevices import Motor
+		from pybricks.parameters import Port, Stop
+		from pybricks.tools import wait
+	
+		hub = CityHub()
 snippet movehub
 	from pybricks.hubs import MoveHub
 	from pybricks.pupdevices import Motor