The Illinois Attorney Registration & Disciplinary Commission announced a series of promotions and new hires last week.According to a commission spokesman, the changes follow the retirement last year of two key staff members — former deputy administrator and chief counsel James J. Grogan and Wendy J. Muchman, the former chief of litigation and professional education.Group managers Peter L. Rotskoff, Althea K. Welsh and Scott Renfroe have all been named deputy ARDC administrators.Rotskoff will serve as deputy …