Replace breadcrumbs with recently viewed menu (#7073)

src/settings/Settings.tsx

@@ -355,6 +355,13 @@ export const SETTINGS: {[setting: string]: ISetting} = {
             new ReloadOnChangeController(),
         ]),
     },
+    "feature_breadcrumbs_v2": {
+        isFeature: true,
+        labsGroup: LabGroup.Rooms,
+        supportedLevels: LEVELS_FEATURE,
+        displayName: _td("Use new room breadcrumbs"),
+        default: false,
+    },
     "RoomList.backgroundImage": {
         supportedLevels: LEVELS_ACCOUNT_SETTINGS,
         default: null,
@@ -711,6 +718,7 @@ export const SETTINGS: {[setting: string]: ISetting} = {
         supportedLevels: LEVELS_ACCOUNT_SETTINGS,
         displayName: _td("Show shortcuts to recently viewed rooms above the room list"),
         default: true,
+        controller: new IncompatibleController("feature_breadcrumbs_v2", true),
     },
     "showHiddenEventsInTimeline": {
         displayName: _td("Show hidden events in timeline"),