The original Sofi’s Crepes — founded nearly 20 years ago in Station North — will close this spring as founder Ann Costlow prepares to retire. Costlow, 66, said Wednesday that she’s ready to focus on other pursuits after two decades in the often grueling restaurant business. “I have been doing this for 20 years and I have loved almost every minute about it,” she said, “but, really, I’m ready to .