Uhm, you download a page full of relative links, dump it in a file, then try to display it. It's not magically going to resolve the relative links. For instance, the "plots are not rendered as ASCII art" is an alt text, displayed because it cannot download the image.

At least you need to throw in a <base> element. Or, if the goal is to show the page in a browser, make a GET URL, and start the browser with that URL.