Fix link to async_redux package (#5224)

Fixes #5212

Author: filiph

src/docs/development/data-and-backend/state-mgmt/options.md

@@ -154,7 +154,7 @@ An approach similar to Provider that is compile-safe and testable. It doesn't ha
 [Accompanying article on Medium]: {{site.flutter-medium}}/animation-management-with-flutter-and-flux-redux-94729e6585fa
 [Animation Management with Redux and Flutter]: https://www.youtube.com/watch?v=9ZkLtr0Fbgk
 [Architect your Flutter project using BLoC pattern]: {{site.medium}}/flutterpub/architecting-your-flutter-project-bd04e144a8f1
-[Async Redux–Redux without boilerplate. Allows for both sync and async reducers]: {{site.pub}}/packages/async_redux/
+[Async Redux–Redux without boilerplate. Allows for both sync and async reducers]: {{site.pub}}/packages/async_redux
 [Basic state management in Google Flutter]: {{site.medium}}/@agungsurya/basic-state-management-in-google-flutter-6ee73608f96d
 [Flutter meets Redux: The Redux way of managing Flutter applications state]: https://medium.com/@thisisamir98/flutter-meets-redux-the-redux-way-of-managing-flutter-applications-state-f60ef693b509
 [BloC Library]: https://felangel.github.io/bloc