Adding course of kotlin (#6577)

courses/free-courses-pt_BR.md

@@ -183,6 +183,7 @@
 ### Kotlin
 
 * [Aprenda Kotlin do zero - Módulo Básico](https://www.udemy.com/kotlin-aprenda-do-zero-modulo-basico/) - Pedro Massango (Udemy)
+* [Curso de Kotlin 2020 | Básico](https://www.youtube.com/playlist?list=PLPs3nlHFeKTr-aDDvUxU971rPSVTyQ6Bn) - Douglas Motta (Youtube)
 * [Desenvolvedor Kotlin Iniciante](https://www.udemy.com/desenvolvedor-kotlin-iniciante/) - Gabriel Ferrari, Adriano Sacardo (Udemy)