By ANNIE COSTABILE and BRIAN HAMILTON / THE ATHLETIC Only two years into their existence, the Golden State Valkyries have won a WNBA championship. They did it with their typical grit and determination, and some sensational shooting from Gabby Williams. The Valkyries beat the Atlanta Dream, 68-63, on Saturday night, winning the first Game 7 in league history. If you are looking for comparisons to what this women’s basketball team has done, consider this: No expansion franchise in the major…
