docs: def sqlite_default():
      '''
      Prepend default scheme if none is specified. This helps provides backwards
      compatibility with old versions of taxtastic where sqlite was the automatic
      default database.
      '''
      def parse_url(url):
          # TODO: need separate option for a config file
          if url.endswith('.db') or url.endswith('.sqlite'):
              if not url.startswith('sqlite:///'):
                  url = 'sqlite:///' + url
          elif url.endswith('.cfg') or url.endswith('.conf'):
              conf = configparser.SafeConfigParser(allow_no_value=True)
              conf.optionxform = str  # options are case-sensitive
              conf.read(url)
              url = conf.get('sqlalchemy', 'url')
  
          return url
      return parse_url