Generate a link to the image placeholder.

        :param width: Width of image.
        :param height: Height of image.
        :return: URL to image placeholder.

def image_placeholder(width: Union[int, str] = 1920,
                          height: Union[int, str] = 1080) -> str:
        """Generate a link to the image placeholder.

        :param width: Width of image.
        :param height: Height of image.
        :return: URL to image placeholder.
        """
        url = 'http://placehold.it/{width}x{height}'
        return url.format(width=width, height=height)