feat: Add notes

lib/features/document_details/view/widgets/add_note_page.dart

@@ -0,0 +1,37 @@
+import 'package:flutter/material.dart';
+import 'package:flutter/widgets.dart';
+import 'package:paperless_api/paperless_api.dart';
+import 'package:paperless_mobile/generated/l10n/app_localizations.dart';
+
+class AddNotePage extends StatefulWidget {
+  final DocumentModel document;
+
+  const AddNotePage({super.key, required this.document});
+
+  @override
+  State<AddNotePage> createState() => _AddNotePageState();
+}
+
+class _AddNotePageState extends State<AddNotePage> {
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: Text(S.of(context)!.addNote),
+      ),
+      body: Column(
+        children: [
+          TextField(
+            decoration: InputDecoration(
+              labelText: S.of(context)!.content,
+            ),
+          ),
+          ElevatedButton(
+            onPressed: () {},
+            child: Text(S.of(context)!.save),
+          ),
+        ],
+      ),
+    );
+  }
+}