Ruben Santiago-Hudson is a familiar face to anyone who watches television or films.  But “Lackawanna Blues” holds a special place in his heart.  He wrote the play to celebrate the woman who raised him in the rural New York town, a woman known as “Nanny.”  It’s been performed on many stages and on TV, but now, as Broadway reopens, it’s found a home at the Samuel J. Friedman theater, with the Manhattan Theatre Company.  Santiago-Hudson joins Cheryl Wills in that theater to talk about the play, which he not only wrote and directed but in which he plays 20 roles, and why it means so much to him.  He also speaks to a cause he’s dedicated himself to: making Broadway a more diverse and inclusive space for people of color, on both sides of the curtain.  It’s something his role as an advisor to the MTC has helped him turn into a reality, as he hired front and back of house staff for his production of “Lackawanna Blues.”  It’s an emotional conversation that looks beyond the simple entertainment value of a Broadway show.