Add JavaScript Course (#9824)

* Add Java and Kotlin free courses in pt-BR

* Add JavaScript course

* Update courses/free-courses-en.md

Co-authored-by: Eric Hellman <eric@hellman.net>

---------

Co-authored-by: Eric Hellman <eric@hellman.net>

courses/free-courses-en.md

@@ -844,6 +844,7 @@
 * [Cycle.js Fundamentals](https://egghead.io/courses/cycle-js-fundamentals) - André Staltz
 * [ES6 and Typescript Tutorial](https://www.youtube.com/playlist?list=PLC3y8-rFHvwhI0V5mE9Vu6Nm-nap8EcjV) - Codevolution, Vishwas Gopinath
 * [Functional Programming in JavaScript](https://www.youtube.com/playlist?list=PL0zVEGEvSaeEd9hlmCXrk5yUyqUag-n84) - Mattias Petter Johansson «Fun Fun Function»
+* [Gentle Introduction to JavaScript](https://youtube.com/playlist?list=PLErOmyzRKOCpmitTOazq3_p74Y-yTQB6A) - Deborah Kurata
 * [Intro to JavaScript ES6 programming](https://www.youtube.com/playlist?list=PL-xu4i_QDSxcoDNeh8rx5-pHCCTOg0XsI)
 * [Intro To JavaScript Unit Testing & BDD](https://www.youtube.com/watch?v=u5cLK1UrFyQ) - Traversy Media
 * [Introduction to ES6+](https://scrimba.com/learn/introtoes6) - Dylan C. Israel (Scrimba)