When the renowned choreographer Akram Khan was commissioned to update the classic “Giselle” for the English National Ballet, he couldn’t simply put new steps to a Romantic-era plot. Beautiful as it is, “Giselle” has a view of ideal womanhood that is insupportable in our century—and it didn’t reflect the women he knew.  In Khan’s 2016 “Giselle,” the title character doesn’t chastely expire from a broken heart; she is a strong woman victimized by more powerful men.  The story still culminates in an act of forgiveness, but in a way that resonates with the era of #MeToo. Vincenzo Lamagna composed the production’s new score. The producer Ngofeen Mputubwele describes the production as not simply a great modern ballet but a model for how to reimagine a story that doesn’t work anymore.