MILWAUKEE — Spencer Jones’ first series as a big leaguer is in the books, but not before collecting his first career hit. The Yankees top prospect got that out of the way Sunday, in the third game of his major league career, smoking an RBI single to center field off Brewers righty Logan Henderson in the second inning of a 4-3 loss at American Family Field . Henderson threw a first-pitch slider and Jones pounced on it, drilling it 106.4 mph off the bat to score José Caballero from second for the 2-0 lead. The milestone hit came on Mother’s Day, with Jones’ mom and family sitting next to the Yankees dugout , as they did all weekend, including his MLB debut Friday night. “It was super exciting,” said Jones, who had the ball in a case sitting in his locker after the game. “I’m glad my family was here to share that with me. Teammates rooting me on, a lot of congratulations. I was excited to get a run across too for the guys.…