Added new embedded section in polish language (#11591)

* Added new embedded section for pl lang

* fixed formatting

* flat embedded category

courses/free-courses-pl.md

@@ -7,6 +7,7 @@
 * [C](#c)
 * [C#](#csharp)
 * [C++](#cpp)
+* [Embedded](#embedded)
 * [HTML and CSS](#html-and-css)
 * [Java](#java)
 * [JavaScript](#javascript)
@@ -54,6 +55,12 @@
 * [PROGRAMOWANIE W C++. KURS OD PODSTAW, DLA KAŻDEGO (VIDEO)](https://www.youtube.com/playlist?list=PLOYHgt8dIdoxx0Y5wzs7CFpmBzb40PaDo) - Mirosław Zelent, Damian Stelmach
 
 
+### Embedded
+
+* [Kurs podstaw Arduino](https://www.forbot.pl/blog/kurs-arduino-podstawy-programowania-spis-tresci-kursu-id5290)
+* [Kurs STM32L4](https://www.forbot.pl/blog/kurs-stm32-l4-wstep-spis-tresci-dla-kogo-jest-ten-kurs-id48575)
+
+
 ### HTML and CSS
 
 * [Kurs CSS](http://www.kurshtmlcss.pl/kurs-css) (Netido Interactive Agency)