readme: star history (#14)

Author: DavidePaglieri

README.md

@@ -79,6 +79,10 @@ We welcome contributions! Please see our [Contributing Guidelines](https://githu
 ## License
 This project is licensed under the MIT License - see the [LICENSE](LICENSE) file for details.
 
+## Star History
+
+[![Star History Chart](https://api.star-history.com/svg?repos=balrog-ai/BALROG&type=Date)](https://star-history.com/#balrog-ai/BALROG&Date)
+
 ## Citation
 If you use BALROG in any of your work, please cite: