By Stephanie Apstein Meet Anna Digger, the U.S. short track star’s answer to combating anxiety—on and off the ice—in her chase for Olympic gold. BEIJING — Maame Biney glides to the line, pulls her skates perpendicular, crouches in anticipation of the starting gun—and disappears. In her place is Anna Digger, rocketing around the speedskating track, slicing past opponents, glaring at everyone. Five hundred meters later, Anna crosses the line and goes right back to being Maame. “Me, Maame, personally, I’m a very chill, like, laidback kind of person,” Biney says. “I think lazy would be the right w…