The pizza has been cleared away and the sixth-, seventh- and eighth-grade girls in Mawiayah Fields’ classroom at South Shore School are ready to learn how to write computer code, USA Today reports. But first, a dozen or so volunteers, who have taken time off work to help on this September afternoon, introduce themselves with stories of how they found their professional calling. “I come from a dysfunctional family, so I like to fix things,” Vazjier Rosario, 27, a Microsoft engineer and mother of three, told them…