feat: implement instance/provide annotations

cherrypick_annotations/lib/cherrypick_annotations.dart

@@ -16,5 +16,6 @@ library;
 export 'src/module.dart';
 export 'src/bind.dart';
 export 'src/provide.dart';
+export 'src/instance.dart';
 export 'src/singleton.dart';
 export 'src/named.dart';

cherrypick_annotations/lib/src/instance.dart

@@ -0,0 +1,17 @@
+//
+// Copyright 2021 Sergey Penkovsky (sergey.penkovsky@gmail.com)
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//      http://www.apache.org/licenses/LICENSE-2.0
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+// ignore: camel_case_types
+class instance {
+  const instance();
+}