As in you want the mod to be part of the default mods packaged with the regular releases?
If so, you’d have to get the mod reviewed and accepted as a core mod, which comes with its own obligations. Not just any mod becomes a core mod, there’s obligations around supporting it, updating it, etc.
If you just mean install a mod to the local version of CDDA you have, then download the mod folder from that github, and there’s a “mods” folder inside the data folder. Drop it in there and you can start a new world with it.