Add TAC description in labs

src/i18n/strings/en_EN.json

@@ -1461,6 +1461,7 @@
         "sliding_sync_server_specify_proxy": "Your server lacks native support, you must specify a proxy",
         "sliding_sync_server_support": "Your server has native support",
         "threads_activity_centre": "Threads Activity Centre (in development)",
+        "threads_activity_centre_description": "Warning: Under active development; reloads Element.",
         "under_active_development": "Under active development.",
         "unrealiable_e2e": "Unreliable in encrypted rooms",
         "video_rooms": "Video rooms",

src/settings/Settings.tsx

@@ -1120,6 +1120,7 @@ export const SETTINGS: { [setting: string]: ISetting } = {
         labsGroup: LabGroup.Threads,
         controller: new ReloadOnChangeController(),
         displayName: _td("labs|threads_activity_centre"),
+        description: _td("labs|threads_activity_centre_description"),
         default: false,
         isFeature: true,
     },