NewCleaner returns a usable Cleaner struct if either w or p are nil it will return an error.

Cleaner wraps the underlying WriteCloser, and handles parsing HTML into Altid-flavoured markdown, to the underlying writer.

Image is an image tag <img src="foo" alt="bar">.

URL is a url tag <a href="something">Msg</a>.

Handler will be called to satisfy both <nav> and <img> elements.

ImgHandler is called when the parser encounters an <img> element.

NavHandler is called when the parser encounters a <nav> element.