docs: add ionic-state (#1359)

Author: jdegand

README.md

@@ -2117,6 +2117,7 @@ for the creation of web applications developed with Angular.
 * [IDEA-Ionic8-extra](https://github.com/iter-idea/IDEA-Ionic8-extra) - [IDEA's](https://www.iter-idea.com/) extra components and services built on Ionic 8, and distributed with different NPM packages.
 * [ionic-component-snippets](https://github.com/LennonReid/ionic-component-snippets) - This repository showcases demos and libraries that aren't officially supported by Ionic yet, but can be useful for developers and their apps.
 * [ionic-header-parallax](https://github.com/RaschidJFR/ionic-header-parallax) - This directive enables a parallax effect on `ion-header` elements to display a cover photo while on top of the page and transition to the normal toolbar when scrolling down.
+* [ionic-state](https://github.com/godenji/ionic-state) - Provides utilities for working with state in Ionic applications.
 
 #### RxJS