Adds "name" parameter to ESC spawn command (#410)

Co-authored-by: StraToN <StraToN@users.noreply.github.com>

addons/escoria-core/game/main_scene.gd

@@ -5,15 +5,5 @@ extends Node
 
 # Start the main menu
 func _ready():
-	if escoria.main_menu_instance == null:
-		if ProjectSettings.get_setting("escoria/ui/main_menu_scene") == "":
-			escoria.logger.report_errors("escoria.gd", 
-				["Parameter escoria/ui/main_menu_scene is not set!"]
-			)
-		else:
-			escoria.main_menu_instance = escoria.resource_cache.get_resource(
-				ProjectSettings.get_setting("escoria/ui/main_menu_scene")
-			).instance()
-	escoria.call_deferred("add_child", escoria.main_menu_instance)
-	
+	escoria.init()