message: Mark static overlay color tables as const
diff: @@ -44,7 +44,7 @@ namespace {
  };
  - std::map<Tile::Overlay, NAS2D::Color> OverlayColorTable =
  + const std::map<Tile::Overlay, NAS2D::Color> OverlayColorTable =
  {
  {Tile::Overlay::None, NAS2D::Color::Normal},
  {Tile::Overlay::Communications, {125, 200, 255}},
  @@ -53,7 +53,7 @@ namespace {
  {Tile::Overlay::Police, NAS2D::Color::Red}
  };
  - std::map<Tile::Overlay, NAS2D::Color> OverlayHighlightColorTable =
  + const std::map<Tile::Overlay, NAS2D::Color> OverlayHighlightColorTable =
  {
  {Tile::Overlay::None, NAS2D::Color{125, 200, 255}},
  {Tile::Overlay::Communications, {100, 180, 230}},
  