Derek and Kate Feinberg bought a small home in a neighborhood they loved and plan to renovate using a third-party loan.Courtesy of Derek and Kate FeinbergDerek and Kate Feinberg fell in love with Wayne, Pa., but couldn't afford a big enough home there.They bought a smaller home in the location they wanted, and plan to renovate it instead.They used a platform that allows them to borrow money based on the post-renovation value of their home.This a…