Add javascript playlist from LearnWebCode (#6498)

* Add javascript free course from LearnWebCode

* add author name

courses/free-courses-en.md

@@ -510,6 +510,7 @@
 * [Object-Oriented JavaScript](https://www.udacity.com/course/object-oriented-javascript--ud711) - Richard Kalehoff (Udacity)
 * [Offline Web Applications](https://www.udacity.com/course/offline-web-applications--ud899) - Google, Michael Wales (Udacity)
 * [Programming Foundations with Javascript, HTML and CSS](https://www.coursera.org/learn/duke-programming-web) - Owen Astrachan, Robert Duvall, Andrew D. Hilton, Susan H. Rodger (Coursera)
+* [The 10 Days of JavaScript](https://www.youtube.com/playlist?list=PLpcSpRrAaOaoIqHQddZOdbRrzr5dJtgSs) - Brad Schiff, LearnWebCode (YouTube)
 * [Understanding RxJS](https://youtube.com/playlist?list=PL55RiY5tL51pHpagYcrN9ubNLVXF8rGVi) - Academind
 * [Vanilla JavaScript](https://www.youtube.com/playlist?list=PLillGF-RfqbbnEGy3ROiLWk7JMCuSyQtX) - Brad Traversy, Traversy Media (YouTube)