Our nonprofit, Open Law Library, works with governments to do exactly this. For example, the DC Council uses our software to codify and publish their laws in xml and html on github: https://github.com/dccouncil/dc-law-xml. If you're interested in getting your government's laws published using git in human- and computer-readable formats, feel free to reach out to me at dgreisen [at] openlawlib [dot] org.