See https://github.com/sartak/keyboard
You can use this configuration with:
qmk cd
cd keyboards/ferris/keymaps/
git submodule add https://github.com/sartak/qmk-config.git sartak
qmk flash -kb ferris/sweep -km sartak
# with whatever modifiers you need