Licensing information is in the majority of the files. Please take note that unless specified, all files are under the arma public licence: APL-ND. You may read about this here: https://www.bohemia.net/community/licenses/arma-public-license-nd
This github is more for the WIKI aspect/code inspection, rather than a place for installation.
You can find the mod at: https://steamcommunity.com/sharedfiles/filedetails/?id=1565793841
The extension mod (includes factions, units etc.) can be found at: https://steamcommunity.com/sharedfiles/filedetails/?id=1632188752