American sprinter Sha’Carri Richardson, who was set to be a breakout star at the Olympic Games later this month, has tested positive for marijuana, putting her participation in the Tokyo games in doubt. The 21-year-old, sporting bright orange hair and an electric personality, roared to victory in the women’s 100-meter sprint at the U.S. Olympic trials, making her a fan favorite as well as a favorite to win gold. The positive test taken at the trials last month means Richardson will likely face a competition ban of some length; the sanction for...