I guess this is one of those items where the headline tells the story. The American Repertory Theater has extended its disco-Shakespeare hit, "The Donkey Show," with an open-ended run on Friday and Saturday nights through the summer, at the club/set Oberon in Harvard Square. The play turns "A Midsummer Night's Dream" into a booty-shaking fantasia that pulls the audience right into the action (and serves them drinks). It's part of new artistic director Diane Paulus' Shakespeare Exploded! festival, which also includes the r&b version of "A Winter's Tale" called "Best of Both Worlds" at the Loeb Drama Center and the eerie nightmare version of "Macbeth" called "Sleep No More" that plays inside a disused school in Brookline. While "Donkey Show" had a long run for Paulus in New York previously, and "Sleep No More" is a creation of the British troupe Punchdrunk, you have to think this fall has been pretty much a triumph for the new boss. I mean, when was the last time Shakespeare at the A.R.T. had to be extended for up to nine months?