NEW YORK — The show curtain has a picture guide for the uninitiated: box braids, cornrows, micro braids, Ghana braids, tree braids. Even, if you’re lucky and the stylist is in the right mood, kinky twists. All of these looks can be found at Jaja’s, the Harlem hair-braiding emporium at the heart of the very lively new Broadway play from Jocelyn Bioh, as directed by Whitney White and co-produced ...