def format_msg(wiki_link: str):
    """Return html formatted email content."""
    contents = f'''
    <!DOCTYPE html>
    <html>
        <body>
            <div style="text-align:center;">
                <h1>Your Weekly Article:</h1>
                <a href="{wiki_link}">{wiki_link}</a>
            </div>
        </body>
    </html>
    '''
    return contents