Miss Piggy, star of ABC’s “The Muppets,” will make a special appearance during the 2015 National Christmas Tree Lighting, presented by the National Park Service and the National Park Foundation, the official charity of America’s national parks. Find out who else has been announced so far at www.thenationaltree.org. An international celebrity, television and feature film star, best-selling author, supermodel, and fashion icon, Miss Piggy will help kick-off the holiday season at the 93rd annual National Christmas Tree Lighting on Thursday, December…