Hey! Glad you decided to contribute to this project.
I'll guide you personally through the process of contributing to the project. First of all, there is several ways of contributing.
The first one would be to fork the project and make your own improvements. If you are familiar with GitHub, you can do this by simply clicking on the "Fork" button. It can be something as simple as adding test cases or even new features.
You can also test rfscss and open an issue on GitHub if you think something can be improved. Even better, you can also implement your suggestion and make a pull request.
Sharing the project is also a way of contributing! If you think someone would be helped by this tool, sharing the knowledge would be amazing.
Anything is fine as long as the code is clean, C++'ish and well documented. Don't hesitate of leaving comments if you think something looks tricky.
Your pull request will be discussed upon and if everything is fine, it will be merged into the develop branch, as the master branch is reserved for releases.