Superintendent Stacy Scott has chosen a new principal to head Stapleton Elementary School in the fall. Joseph Smith, principal at Leeds Elementary School in Northampton, was chosen after Stapleton’s current principal, William McDonald, resigned to look at jobs closer to his Western Massachusetts home, Scott said in an e-mail. Framingham officials were still negotiating Smith’s contract as of Wednesday afternoon, Scott said. Smith has headed up Leeds Elementary for three years, and was the assistant principal at Crocker Farm Elementary School in Amherst for two years, according to Framingham officials. He has master’s degrees in reading and in special education from Sage Graduate School in Albany, and completed his undergraduate degree at the State University of New York at Albany. Currently a resident of Easthampton, Smith has plans to relocate to the Framingham area.