Chargers add CB William Middleton

The Chargers added some experienced depth to their secondary Sunday, signing former Jaguars cornerback William Middleton, the club said. Middleton (5-10, 190) made 12 regular-season starts in four NFL seasons with Jacksonville.  In 2012, he appeared in 10 games (three starts), notching 20 tackles. Middleton turns 28 on Monday. The Chargers signed another Jaguars cornerback, Derek…