There’s a moment in Howard, Don Hahn’s incredible documentary about the life of Oscar-winning lyricist Howard Ashman, who contributed unforgettably to The Little Mermaid, Aladdin and Beauty and the Beast, that is so quick you will probably miss it. It’s in a section of the movie that details Disney’s attempt to woo the lyricist and writer in the late 1980s, after his frustrating experience on the film version of Little Shop of Horrors and after his would-be Broadway hit Smile had a spectacular flameout. Hahn shows a letter from then-Disney executive Jeffrey Katzenberg, …