“The Peanut Butter Falcon” is a less-than enticing title for a movie. But don’t let that keep you from going to any of the several local theaters showing the indie heart-warmer. It features an impressive and refreshing leading performer: Zack Gottsagen, who has Down syndrome. He escapes his state-designated nursing home and pairs up with Tyler (Shia LaBeouf), a scruffy troublemaker on the run. There’s plenty of laughs along the way. But in between is the drama of two very different souls searching for something — perhaps the same thing.