Added basic elevator system

client/Scripts/Entities/ElevatorDoor.gd

@@ -0,0 +1,10 @@
+extends "res://Scripts/Entities/Door.gd"
+
+export var level_index : int = 0
+
+func on_elevator_stop(index):
+	if index == level_index:
+		unlock()
+		open()
+	else:
+		lock()