BOSTON — Publishers Lunch reported recently that Christopher Castellani, artistic director at the Boston-based GrubStreet and a Guggenheim fellow, landed a book deal with Viking. Castellani’s “Leading Men,” a book about “the tempestuous 14-year relationship between Tennessee Williams and his lover Frank Merlo, and their transformative friendship with an aspiring young Swedish actress, whom they first meet in 1953 in Italy at one of Truman Capote’s notorious parties,” was acquired by Paul Slovak at Viking, according to Publishers Lunch.