Add disableLetterboxing setting to game options

src/dusk/settings.cpp

@@ -76,6 +76,7 @@ UserSettings g_userSettings = {
         .resampler {"game.resampler", Resampler::Bilinear},
         .enableMapBackground {"game.enableMapBackground", true},
         .disableCutscenePillarboxing {"game.disableCutscenePillarboxing", false},
+        .disableLetterboxing {"game.disableLetterboxing", false},
         .enableHighQualityMinimapTextures {"game.enableHighQualityMinimapTextures", true},
 
         // Audio
@@ -284,6 +285,7 @@ void registerSettings() {
     Register(g_userSettings.game.shadowResolutionMultiplier);
     Register(g_userSettings.game.enableMapBackground);
     Register(g_userSettings.game.disableCutscenePillarboxing);
+    Register(g_userSettings.game.disableLetterboxing);
     Register(g_userSettings.game.enableHighQualityMinimapTextures);
     Register(g_userSettings.game.enableFastIronBoots);
     Register(g_userSettings.game.canTransformAnywhere);