Former New Mexico Gov. Bill Richardson is planning to travel to Russia in the near future for talks aimed at finding a deal to free the detained WNBA star Brittney Griner, a source with knowledge of the proposed trip told ABC News.Richardson, who also served as the U.S. ambassador to the United Nations and energy secretary in the Clinton administration, played a role in achieving a prisoner exchange in April that saw Russia release former U.S. Marine Trevor Reed after nearly two and a half years in captivity.He is expected to go to Moscow in the next couple of weeks,...