import typing


def format_author(data: typing.Dict[str, typing.Any]) -> str:
    """
    Format a GitHub author JSON into a Markdown message.
    """
    if "name" in data and "email" in data:
        return f"**{data['name']}** (*{data['email']}*)"
    else:
        return f"[**{data['login']}**]({data['html_url']})"