Head's up, Chick-fil-A, the Golden Arches are coming for you. McDonald's Corp. (NYSE: MCD) is making a move to becoming a "credible chicken player," according to internal McDonald’s documents reviewed by Bloomberg News, and that means flying toward the successes of Chick-fil-A Inc. Bloomberg reports that the venerable Illinois-based burger joint sent a letter to franchises about making a move out of nuggets territory and into more quality chicken -- under the project code name: "Better Chicken."…