Update free-courses-pt_BR.md (#3289)

free-courses-pt_BR.md

@@ -17,6 +17,7 @@
 * [PHP](#php)
 * [Python](#python)
 * [Ruby](#ruby)
+* [Shell](#shell)
 * [Swift](#swift)
 
 
@@ -138,6 +139,11 @@
 * [Ruby Para Iniciantes](https://www.udemy.com/ruby-para-iniciantes/) - Bruno Paulino (Udemy)
 
 
+### Shell
+
+* [Conceitos de Programação em Shell Script](https://www.udemy.com/conceitos-de-programacao-em-shell-script/) - TemWeb (Udemy)
+
+
 ### Swift
 
 * [Aprenda a fazer apps para iPhone - Swift e Firebase](https://www.udemy.com/aprenda-a-fazer-apps-para-iphone/) - Claudio Zani Silva (Udemy)