As Chicago’s live theaters continue to go dark for now because of the COVID-19 surge, there is a little light out there to brighten us. “Winnie-the-Pooh” is scheduled to open onstage March 15 at the Mercury Theater, 3745 N. Southport.I know it is a little early to announce the arrival of everybody’s “silly old bear,” but I have to admit that he is one of my all-time favorites, and I would not want you or your family to miss this charming tale of Winnie and all of his friends from the Hundred Acre Wood.I also have to admit …