Shein is getting into the reality-TV biz—and it’s not pulling any punches. The Chinese fast-fashion e-tailer announced Tuesday its upcoming Shein x 100K Challenge, a four-episode “Project Runway”-like series featuring judges such as fashion designer Christian Siriano, former J.Crew creative director Jenna Lyons, Zendaya’s stylist Law Roach and TV personality-slash-Good American founder Khloé Kardashian. The…