Returns the website location for projex software.
    
    :param      app  | <str> || None
                mode | <str> (home, docs, blog, dev)
    
    :return     <str>

def website(app=None, mode='home', subcontext='UserGuide'):
    """
    Returns the website location for projex software.
    
    :param      app  | <str> || None
                mode | <str> (home, docs, blog, dev)
    
    :return     <str>
    """
    base_url = WEBSITES.get(mode, '')

    if app and base_url:
        opts = {'app': app, 'base_url': base_url}
        base_url = SUBCONTEXT_MAP.get((mode, subcontext), base_url)
        base_url %= opts

    return base_url