Adds 'Internationalization with vue-i18n' course (#4993)

* Adds 'Internationalization with vue-i18n' course

Adds the free 'Internationalization with vue-i18n' course on Vue.js from https://vueschool.io

* Updated the Vue.js courses list to alphabetical order

free-courses-en.md

@@ -388,6 +388,7 @@
 
 #### Vue.js
 
+* [Internationalization with vue-i18n](https://vueschool.io/courses/internationalization-with-vue-i18n)
 * [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)