The Provincetown Book Festival has added a slew of writers to the lineup for this year’s event, which kicks off Sept. 16. P-town poets Elizabeth Bradfield, Kelle Groom, and Jill McDonough will join Cape Cod fiction writer Sally Cabot Gunning, Portuguese-American writer Katherine Vaz, author of “Our Lady of the Artichokes,’’ Jamaican-born novelist Nicole Dennis-Benn, author of “Here Comes the Sun,’’ 2016 Guggenheim Fellow Paul Lisicky, and novelists Alexander Chee and Tim Murphy, among many others.