To keep the drivers update, and also like that peoples can 'convert' they own distro easily.
If you want to install the drivers using the precompiled files just use sudo pacman -U in the 'Compiled/x86_64' folder for each files.
If you want to compile and install the drivers just use makepkg -sri in for each folder inside 'SRC'.
You can find a better explanation here
you can leave a issue.