message: Mark difficultyTable as const
diff: @@ -24,7 +24,7 @@ enum class Difficulty
  };
  -inline std::map<std::string, Difficulty> difficultyTable
  +inline const std::map<std::string, Difficulty> difficultyTable
  {
  {"Beginner", Difficulty::Beginner},
  { "Easy", Difficulty::Easy },
  