Danny Ainge’s storied career with the Boston Celtics, both as a player and as president of basketball operations will soon come to a close, as was announced Wednesday in news that took the sports world by storm. Ainge’s position will be filled by current Celtics head coach Brad Stevens. Ainge, who brought two NBA titles to Boston as a player and one NBA title as an executive, says his decision to step down was prompted by his family’s concern following a heart attack two years ago. “I started thinking about my life and what I’d like to accomplish. I don’t know what my future holds. I don’t have any plans,” Ainge said Wednesday.