feat: add option to show download speed in megabits

src/types/level.types.ts

@@ -81,6 +81,7 @@ export interface UserPreferences {
   enableAutoInstall?: boolean;
   seedAfterDownloadComplete?: boolean;
   showHiddenAchievementsDescription?: boolean;
+  showDownloadSpeedInMegabits?: boolean;
   downloadNotificationsEnabled?: boolean;
   repackUpdatesNotificationsEnabled?: boolean;
   achievementNotificationsEnabled?: boolean;