Refactor: Added explicit typing and void return types

- Introduced explicit typing to variables and functions across multiple scripts for better code clarity.
- Specified 'void' as the return type for functions that do not return a value.
- Removed redundant code in some scripts.

scenes/scripts/main_menu.gd

@@ -1,18 +1,18 @@
 extends Level
 class_name MainMenu
 
-@onready var level_select = get_node("%MenuButton")
-@onready var high_scores = get_node("%HighScores")
-@onready var exit_button = get_node("%ExitGame")
+@onready var level_select : MenuButton = get_node("%MenuButton")
+@onready var high_scores : Button = get_node("%HighScores")
+@onready var exit_button : Button = get_node("%ExitGame")
 
-func _ready():
+func _ready() -> void:
 	level_select.get_popup().id_pressed.connect(_on_item_menu_pressed)
 	high_scores.connect("pressed", Callable(self, "on_high_scores_pressed"))
 	exit_button.connect("pressed", Callable(self, "on_exit_pressed"))
 	update_game_state()
 
 
-func _on_item_menu_pressed(id):
+func _on_item_menu_pressed(id : int) -> void:
 	## Load the appropriate level based on the selection that has been made 
 	Log.pr(id)
 
@@ -36,12 +36,12 @@ func _on_item_menu_pressed(id):
 			# Load level 6
 			SceneMgr.load_scene("LEVEL6")
 
-func on_high_scores_pressed():
+func on_high_scores_pressed() -> void:
 	## Load the high scores screen
 	Log.pr("High scores button pressed")
 	SceneMgr.load_scene("HIGHSCORES")
 	pass
 
-func on_exit_pressed():
+func on_exit_pressed() -> void:
 	# Quit the game 
 	get_tree().quit()