Here’s how you know that the proposal to name the football field at Penn State’s Beaver Stadium after Joe Paterno is a terrible idea: No one knew about it. No one knew the idea existed, because no one had tried to make the case out in the open first. The people reportedly lobbying for it — a cluster of university trustees — wanted to keep their campaign quiet, and they were apparently willing to flout Pennsylvania law to make their case behind closed doors, and that’s reason enough to tell them to stick it. Spotlight PA did Thursday what it’s supposed to do, revealing that these trustees had m…