KANSAS CITY, Mo. — Kansas City Royals rookie catcher MJ Melendez singled and scored the go-ahead run in the sixth inning on his fellow rookie Emmanuel Rivera’s RBI triple, then for good measure Melendez tacked on a couple insurance runs late with his second major-league home run to help secure a series-tying victory and set up a rubber match. The young hitters in the lineup were the driving force behind much of the offense Wednesday night as the Royals smashed 12 hits and four extra-base hits (including two home runs) in a 6-2 win over the Chicago White Sox in front of an announced 13,504 at K…