Makes sure the config file exists.

    :raises: :class:`epab.core.new_config.exc.ConfigFileNotFoundError`

def _ensure_config_file_exists():
    """
    Makes sure the config file exists.

    :raises: :class:`epab.core.new_config.exc.ConfigFileNotFoundError`
    """
    config_file = Path(ELIBConfig.config_file_path).absolute()
    if not config_file.exists():
        raise ConfigFileNotFoundError(ELIBConfig.config_file_path)