docs: add Bare Metal C++ guide to C++ section

- Add 'Bare Metal C++' online book by Alexey Rybachuk

Author: AntonioBerna

README.md

@@ -445,6 +445,7 @@ Low-level languages like C and assembly provide direct hardware access, enabling
 
 - [📝 Modern C++ in Embedded Development: (Don't Fear) The ++](https://www.embeddedrelated.com/showarticle/1532.php)
 - [📝 C++ On Embedded Systems](https://blog.mbedded.ninja/programming/languages/c-plus-plus/cpp-on-embedded-systems/)
+- [📝💎 Bare Metal C++ - Alexey Rybachuk](https://arobenko.github.io/bare_metal_cpp/)
 - [🎞️💎 C++ in Constrained Environments - Bjarne Stroustrup - CppCon 2022](https://www.youtube.com/watch?v=2BuJjaGuInI)
 - [🎞️👶 C++ Tutorial for Beginners - Full Course](https://www.youtube.com/watch?v=vLnPwxZdW4Y)
 - [🎞️ C++ by The Cherno (YouTube Playlist)](https://youtube.com/playlist?list=PLlrATfBNZ98dudnM48yfGUldqGD0S4FFb)