started adding completion system

scripts/completion_counter.gd

@@ -0,0 +1,16 @@
+extends Node
+
+signal unlock
+
+@export var nodes_needed: Array[Completer]
+var uncompleted: int
+
+func _ready():
+	uncompleted = nodes_needed.size()
+	for node in nodes_needed:
+		node.completed.connect(complete)
+
+func complete():
+	uncompleted -= 1
+	if uncompleted == 0:
+		unlock.emit()