Update README.md

Author: sir-gon

README.md

@@ -27,6 +27,7 @@ Developed with TDD.
 - JSON reading with [@nlohmann/json](https://github.com/nlohmann/json)
 
 [![C++17](https://img.shields.io/badge/C%2B%2B-00599C?style=for-the-badge&logo=c%2B%2B&logoColor=white)](https://en.cppreference.com/w/cpp/17)
+[![CMake](https://img.shields.io/badge/CMake-%23008FBA.svg?style=for-the-badge&logo=cmake&logoColor=white)](https://cmake.org/)
 [![Docker](https://img.shields.io/badge/docker-%230db7ed.svg?style=for-the-badge&logo=docker&logoColor=white)](https://www.docker.com/)
 
 Go to [Install and run](#install-and-run)