大幅変更＆環境バージョンアップ

lib/provider/map_state_provider.dart

@@ -0,0 +1,18 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:gifunavi/model/map_state_instance.dart';
+
+final mapStateNotifierProvider =
+    StateNotifierProvider<MapState, MapStateInstance>((ref) {
+  return MapState();
+});
+
+class MapState extends StateNotifier<MapStateInstance> {
+  MapState() : super(MapStateInstance());
+
+  @override
+  MapStateInstance get state => super.state;
+
+  void startGame(MapStateInstance mi) {
+    state = mi;
+  }
+}