If you entered this repo, you probably already know how to deal with them, but if not, there are some instructions:
rename i3 config file to 'config' and put it into $HOME/.config/i3/
rename cava file to 'config' and put it into $HOME/.config/cava/
rename the polybar configs to 'config.ini' and put it into $HOME/.config/polybar/ (remember to use just one of the files, just put both files in the directory if you have some sort of Polybar Theme Switcher or smth like that.)
Enjoy it!