gd: added menu template

menus/scenes/game_scene/tutorial_manager.gd

@@ -0,0 +1,19 @@
+extends Node
+@export var tutorial_scenes : Array[PackedScene]
+@export var open_delay : float = 0.25
+@export var auto_open : bool = false
+
+func open_tutorials() -> void:
+	if open_delay > 0.0:
+		await get_tree().create_timer(open_delay, false).timeout
+	for tutorial_scene in tutorial_scenes:
+		var tutorial_menu : OverlaidMenu = tutorial_scene.instantiate()
+		if tutorial_menu == null:
+			push_warning("tutorial failed to open %s" % tutorial_scene)
+			return
+		get_tree().current_scene.call_deferred("add_child", tutorial_menu)
+		await tutorial_menu.tree_exited
+
+func _ready() -> void:
+	if auto_open:
+		open_tutorials()