NEW YORK — If the breathless punctuation in the title wasn’t a giveaway, “Gutenberg! The Musical!” begins with a joke about the James Earl Jones Theatre being the “the only Broadway theater named for a Sith Lord.” If that tickles your nerdy funny bone, you’ll likely be on board all night with the double act of Andrew Rannells and Josh Gad, a self-aware reprise of Elder Price and Elder Cunningham in “The Book of Mormon,” except that Rannells and Gad now are playing Doug and Bud, a pair of lovable New Jersey dudes dreaming of writing and starring in a...