fix installation instructions for user-settings that were stale

Signed-off-by: Fredrik Adelöw <freben@gmail.com>

.changeset/loud-dots-sit.md

@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-user-settings': patch
+---
+
+Update installation instructions

plugins/user-settings/README.md

@@ -29,11 +29,11 @@ import { Settings as SidebarSettings } from '@backstage/plugin-user-settings';
 Add the page to the App routing:
 
 ```ts
-import { Router as SettingsRouter } from '@backstage/plugin-user-settings';
+import { UserSettingsPage } from '@backstage/plugin-user-settings';
 
 const AppRoutes = () => (
   <Routes>
-    <Route path="/settings" element={<SettingsRouter />} />
+    <Route path="/settings" element={<UserSettingsPage />}>
   </Routes>
 );
 ```