Director Lisa Immordino Vreeland has taken the guard rails off of her newest documentary so that her audience is left only with the subjects themselves, a move that will confound those used to the spoon-fed style so prevalent in the genre (and delight those sick of just that). “Truman & Tennessee: An Intimate Conversation” discards the talking-heads so the subjects, two of the most celebrated literary minds of their generation, can unspool the mysteries of their lives in their own words. There aren’t any easy answers to be found as a result, and while some audiences might struggle to draw out a manageable “lesson” about the writers, 20th-century celebrity, addiction, or the fickle nature of success, others might walk away with a deeper understanding of who Truman Capote and Tennessee Williams were as people.