update examples

examples/fpdart_http/lib/api.dart

@@ -10,19 +10,19 @@ Effect<http.Client, HttpError, http.Response> get(
 }) =>
 
     /// 2️⃣ Use the Do notation with the `gen` constructor
-    Effect.gen((_) async {
+    Effect.gen(($) async {
       /// 3️⃣ Extract the dependency using `env` (environment)
-      final client = _.sync(Effect.env());
+      final client = $.sync(Effect.env());
 
       /// 4️⃣ Perform a request, catch errors, extract the response
-      final response = await _.async(Effect.tryCatch(
+      final response = await $.async(Effect.tryCatch(
         execute: () => client.get(url, headers: headers),
         onError: (_, __) => const RequestError(),
       ));
 
       /// 5️⃣ Use plain dart code to check for valid status
       if (response.statusCode != 200) {
-        return _.sync(Effect.fail(const ResponseError()));
+        return $.sync(Effect.fail(const ResponseError()));
       }
 
       /// 6️⃣ Return extracted/valid response

examples/fpdart_http/lib/main.dart

@@ -12,7 +12,8 @@ void main() async {
           () => print(response.body),
         ),
       )
-      .runFuture(
+      .provide(
         http.Client(),
-      );
+      )
+      .runFuture();
 }