Add Vuex for Everyone to courses (#4057)

Add Vuex for Everyone by VueSchool to list of courses

free-courses-en.md

@@ -311,6 +311,7 @@
 * [Intro to Vue 2](https://www.vuemastery.com/courses/intro-to-vue-js/vue-instance)
 * [Intro to Vue 3](https://www.vuemastery.com/courses/intro-to-vue-3/intro-to-vue3)
 * [Vue.js Fundamentals](https://vueschool.io/courses/vuejs-fundamentals)
+* [Vuex for Everyone](https://vueschool.io/courses/vuex-for-everyone)
 
 
 ### Kubernetes