Added The Vue.js Handbook to Vue links (#4045)

* Added The Vue.js Handbook to Vue links

Updated free programming books list to include The Vue.js Handbook

* Fix Alphabetical order

* Update free-programming-books.md

free-programming-books.md

@@ -1809,6 +1809,7 @@ Kerridge (PDF) (email address *requested*, not required)
 #### Vue.js
 
 * [Learning Vue.js](https://riptutorial.com/Download/vue-js.pdf) (PDF)
+* [The Vue.js Handbook](https://flaviocopes.nyc3.digitaloceanspaces.com/vue-handbook/vue-handbook.pdf) - Flavio Copes (PDF)
 * [Vue Essential Cheatsheet](https://www.vuemastery.com/pdf/Vue-Essentials-Cheat-Sheet.pdf) (PDF)