If there's one thing that makes any TV show feel more chic, it's a prep school setting (hello Gossip Girl), and FX's brand new show The Shards is no exception. I got a first look at the upcoming series thanks to the Disney Upfront this year, and it promises to be steamy, surprising, and something that doesn't let you go. Palm Royale's Kaia Gerber leads the cast, which automatically tells me this will be the "it girl" show of the fall.Here's ever…