implemented user service (no auth!)

backend-dart/lib/interfaces/http/router.dart

@@ -1,4 +1,4 @@
-import 'package:backend_dart/application/user_service/user_service_provider.dart';
+import 'package:backend_dart/application/service/user_service_provider.dart';
 import 'package:riverpod/riverpod.dart';
 import 'package:shelf/shelf.dart';
 import 'package:shelf_router/shelf_router.dart';
@@ -15,10 +15,10 @@ Router getRouter(ProviderContainer container) {
     return Response.ok('Server is running');
   });
 
-  // UserService instanzieren
+  // Services
   final userService = container.read(userServiceProvider);
 
-  // UserService-Router an Haupt-Router binden
+  // UserService-Router
   router.mount('/users/', userService.router.call);
 
   return router;