Add paste.gnome.org

[Xion]

A little tricky. Looks like the raw URL has some additional junk in its:

• HTML one: https://paste.gnome.org/prwmyffvo
• raw one: https://paste.gnome.org/prwmyffvo/**2wig5o**/raw

So in order to fetch it, we'll first need to hit the HTML URL, find the "Raw" link in the HTML, and go to the URL there. This may require sucking in an HTML parser crate as a dependency :(