ignore hidden files when checking for empty output folder

    if cfg.output_path.is_dir():

        file_list = [

            f.resolve().absolute()

            for f in cfg.output_path.iterdir()

            for f in cfg.output_path.iterdir() if not i.name.startswith(".")

        ]

        if len(file_list) != 0:

            raise ValueError("Output folder is not empty. Please delete or move files and folders.")