Add Curso Intensivo de Next.js & React (#6120)

Moving course to javascript section

courses/free-courses-pt_BR.md

@@ -164,6 +164,7 @@
 ### JavaScript
 
 * [Curso Grátis de JavaScript e ECMAScript para Iniciantes](https://www.youtube.com/playlist?list=PLHz_AreHm4dlsK3Nr9GVvXCbpQyHQl1o1) - Curso em Vídeo
+* [Curso Intensivo de Next.js & React](https://www.cod3r.com.br/courses/curso-intensivo-next-react) - Leonardo Leitão (Cod3r)
 * [Curso Starter ES6, Node, React e React Native](https://app.rocketseat.com.br/discover/courses) - Rocketseat
 * [Fast & Furious](https://www.youtube.com/playlist?list=PLy5T05I_eQYOoUz2TtAqq35RLCc-xBZCe) - Codecasts