Add Polish book about C++ (#7592)

* Add Polish book about C++

* fix: remove MIMUW from creators. it's a publisher platform

Co-authored-by: David Ordás <[email protected]>

Author: mdbrnowski

Diff for: books/free-programming-books-pl.md

@@ -86,6 +86,7 @@
 * [Kurs C++](http://cpp0x.pl/kursy/Kurs-C++/1) - Piotr Szawdyński
 * [Kurs podstaw Arduino](https://forbot.pl/blog/kurs-arduino-podstawy-programowania-spis-tresci-kursu-id5290) - forbot.pl
 * [Megatutorial "Od zera do gier kodera"](http://xion.org.pl/productions/texts/coding/megatutorial/) - Karol Kuczmarski
+* [Programowanie obiektowe i C++](https://mst.mimuw.edu.pl/wyklady/poc/wyklad.pdf) - Janusz Jabłonowski (PDF)
 
 
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