Add door synchronization feature

lang/en.json

@@ -4,6 +4,16 @@
 			"lockedDoorAlert": {
 				"name": "Locked Door Alert",
 				"hint": "Send a message in chat when a player tried to open a locked door"
+			},
+			"synchronizedDoors": {
+				"name": "Synchronized Doors",
+				"hint": "Synchronize the state of configured doors"
+			}
+		},
+		"ui": {
+			"synchronizedDoors": {
+				"description": "State changes of doors in the same synchronization group will be synchronized across scenes. Leave blank to disable synchronization for this door.",
+				"groupName": "Synchronization Group"
 			}
 		}
 	}