Opinion by Ted Potrikus: A string of Merls: … puzzles that entertain It’s not just a crossword puzzle, it’s a Merl Reagle crossword puzzle. Mr. Reagle stole the show — unintentionally, I’m sure — in the 2006 movie “Wordplay.” It’s a documentary about crossword tournaments and the people who compete therein; The New York Times crossword editor and NPR star Will Shortz take up a lot of space in the movie, which also features former President Bill Clinton, Baseball Hall…