This article contains major spoilers for the third episode of “American Horror Story: Double Feature.”“AHS: Double Feature” is the fifth season of the Ryan Murphy series that Adina Porter has appeared on, and so far it looks like the most tonally level of the bunch — she previously had a one-episode spot on “Murder House,” and starring roles on “Roanoke,” “Cult” and “Apocalypse.” And as “AHS” fans know those last three in particular get pretty dang silly.“Double Feature,” by contrast, has a much