[docgnome]

So I wanted to be able to click on a link to the HN comments thread of articles downloaded with the Hacker News Recipe. So I made it do that. Not being familiar with calibre recipes I'm sure I've made a pig's breakfast of it. But it does work! Hurray! If someone would like to take a look and help me clean it up that would be nice.

Also I wasn't sure what the etiquette for editing someone else's recipe was exactly. So for author I just tacked my name on the end. Hope that's OK.