Recover "Adds express js crash course" #5055 (#5503)

* Update free-courses-en.md

Added ExpressJS

* Avoid single items sections

Review EbookFoundation/free-programming-books#5055 @alok8bb

Co-authored-by: alok-cmd <73450969+alok-cmd@users.noreply.github.com>

* Fix attributions / platform @bradtraversy

PR review EbookFoundation/free-programming-books#5055 @alok8bb

Co-authored-by: alok-cmd <73450969+alok-cmd@users.noreply.github.com>

Co-authored-by: alok-cmd <73450969+alok-cmd@users.noreply.github.com>

courses/free-courses-en.md

@@ -433,6 +433,7 @@
 #### NodeJS
 
 * [Beginner's Series to: Node.js](https://youtube.com/playlist?list=PLlrxD0HtieHje-_287YJKhY8tDeSItwtg) - Microsoft Developer (YouTube)
+* [Express JS Crash Course](https://www.youtube.com/watch?v=L72fhGm1tfE) - Brad Traversy, Traversy Media (Youtube)
 * [Node.js API Development for Beginners](https://www.udemy.com/course/node-js-api-tutorial/) (Udemy)
 * [Node.js Basics](https://www.youtube.com/playlist?list=PLqq-6Pq4lTTa-d0iZg41U2RDqECol9C5B) - Java Brains (Youtube)