It's "America's Finest News Source" ... or so it claims. The Onion, a Wisconsin-bred satirical news outlet — once a newspaper but now read only online — has a new owner. Jeff Lawson, the co-founder and recently departed CEO of San Francisco software company Twilio, has purchased The Onion. “Alright, the news is out — yes, I bought The Onion,” Lawson posted on LinkedIn on Thursday. The Onion is now based in Chicago, but it was founded as a print publication three decades ago by Tim…