A new documentary tells the little-known tale of the heart-wrenching custody dispute over one of Chicago’s most beloved residents — a dinosaur named Sue. Today, Sue stands tall and comfortably at home in the central atrium of the Field Museum of Natural History, which purchased the dinosaur 17 years ago. But as “Dinosaur 13” recounts, in the decade prior to Sue’s debut at the museum, her future was not so certain. Though Sue’s full story begins more than 65 million years ago, the …