Six weeks ago, the Broncos might have gone three-and-out. Six weeks ago, rookie quarterback Bo Nix might have let his feet get happy, might have tried to bail from the pocket or sailed a throw. Six weeks ago, Sean Payton didn’t have a clear feel for how to can-opener an opposing defense with the players on his Denver offense. Six weeks ago is a long time gone in Broncos Country. Nix’s development — and his offensive rookie of the year campaign — shifted into warp speed Sunday when he completed 28 of 33 passes for 307 yards and four touchdowns and led the Broncos to a 38-6 blowout of Atlanta. The result?