NEW YORK — Former New York City Mayor Bill de Blasio announced Friday that he’s running for Congress after months of speculation over where he’d next set his political sights. The ex-mayor made his campaign for New York’s 10th Congressional District official in a surprise appearance on MSNBC’s “Morning Joe” program, citing “polls” as the justification for throwing his hat in the ring. “The polls show the people are hurting, they need help, they need help fast and they need leaders who can actually get them help now, and I know how to do it,” de Blasio said. “I do know how to do it from years o…