added bookmarks page

lib/pages/bookmarks_page.dart

@@ -0,0 +1,35 @@
+import 'package:flutter/material.dart';
+
+import '../service/bookmarks_provider.dart';
+import '../service/storage.dart';
+
+class BookmarksPage extends StatelessWidget {
+  const BookmarksPage({super.key});
+
+  static const String routeName = '/bookmarks';
+
+  @override
+  Widget build(BuildContext context) {
+    if (BookmarksProvider.selectedCollectionId == null) {
+      Navigator.of(context).pop();
+    }
+    final bookmarks = Storage.loadBookmarksForCollection(
+      BookmarksProvider.selectedCollectionId!,
+    );
+
+    BookmarksProvider.selectedCollectionId == null;
+
+    return Scaffold(
+      appBar: AppBar(
+        title: Text(
+          Storage.loadCollections()
+              .firstWhere((c) => c.id == BookmarksProvider.selectedCollectionId)
+              .name,
+        ),
+      ),
+      body: ListView(
+        children: bookmarks.map((e) => ListTile(title: Text(e.name))).toList(),
+      ),
+    );
+  }
+}