Here’s a bit of service journalism: when you talk to Caleb Hearon about his hometown of Chillicothe, Missouri — which plays a big role in his screenwriting feature film debut, “Trash Mountain” — it’s pronounced Chil-a-caw-thee. (It’s pronounced wrong so often, the fact I said it correctly to Hearon gave up the game pretty quickly that I am also originally from the area.) Though certainly funny, “Trash Mountain” (directed by Kris Rey and premier…