fix: dart sdk package name (#671)

Author: charIeszhao

docs/quick-starts/framework/flutter/_integration.mdx

@@ -7,7 +7,7 @@ import ConfigureRedirectUri from '../../fragments/_configure-redirect-uri.mdx';
 Import the `logto_dart_sdk` package and initialize the `LogtoClient` instance at the root of your application.
 
 ```dart
-import 'package:logto_dart_quick-starts/logto_dart_sdk.dart';
+import 'package:logto_dart_sdk/logto_dart_sdk.dart';
 import 'package:http/http.dart' as http;
 
 void main() async {

docs/quick-starts/framework/flutter/_tip.md

@@ -2,7 +2,7 @@
 
 - Flutter SDK is written based on [Dart](https://dart.dev/).
 - The SDK dart package is available on [pub.dev](https://pub.dev/packages/logto_dart_sdk) and Logto [github repository](https://github.com/logto-io/dart).
-- The example is written using the [Flutter material](https://flutter.dev). The sample project is available on [pub.dev](https://pub.dev/packages/logto_dart_quick-starts/example) and our [github repository](https://github.com/logto-io/dart).
+- The example is written using the [Flutter material](https://flutter.dev). The sample project is available on [pub.dev](https://pub.dev/packages/logto_dart_sdk/example) and our [github repository](https://github.com/logto-io/dart).
 - Supported
 - The SDK is suitable for Android and iOS platforms only.