Add html course in EN (#9916)

* Add Java and Kotlin free courses in pt-BR

* add html course

courses/free-courses-en.md

@@ -746,6 +746,7 @@
 * [CSS Tutorials](https://youtube.com/playlist?list=PLDyQo7g0_nsUjf046cCHKJ16U1SoXrElZ) - Dev Ed
 * [CSS3 tutorial for beginners \| Learn CSS3](https://www.udemy.com/course/css3-tutorial-for-beginners-learn-css3/) - Udemy
 * [Flexbox in 30 Days](https://github.com/samanthaming/Flexbox30) - Samantha Ming
+* [Gentle Introduction to HTML for Beginners](https://www.youtube.com/playlist?list=PLErOmyzRKOCpmPEZIkblP-0sNufXbvXJL) - Deborah Kurata
 * [Get to know HTML Learn HTML Basics](https://www.udemy.com/course/html-online-course/) - Laurence Svekis (Udemy)
 * [HTML & CSS](https://www.youtube.com/playlist?list=PLillGF-RfqbZTASqIqdvm1R5mLrQq79CU) - Brad Traversy, Traversy Media
 * [HTML & CSS Crash Course](https://www.youtube.com/playlist?list=PL4cUxeGkcC9ivBf_eKCPIAYXWzLlPAm6G) - The Net Ninja (Shaun Pelling)