Shaky Knees, arguably one of the biggest music festivals in the Southeast, will return to Atlanta’s Central Park in May. This year’s lineup includes more than 60 acts performing on four stages over three days, with aughts rockers The Killers and The Muse, and neo-folkies The Lumineers getting top billing. Yeah Yeah Yeahs, Cypress Hill, Surf Curse and Digable Planets …