Git/github doesn' provide "Go to definition" and original post was about uselessness of committing law texts into git.
Let's leave github out of the discussion. That's a completely different beast. (And funny enough, github does provide 'go to definition' for some languages.)
So my point was that git is obviously useful for source code of programs.
And as you point out, git does not provide 'go to definition' for source code of programs.
Hence I suggest that the inability of git to provide cross-references in legal text is about as relevant (or rather irrelevant) to the discussion at hand as git's inability to provide cross-references is source code.
Does this make sense?
Git is unnecessary here anyway.
Git is useful for collaboration of multiple people on the same project. Is law making a collaboration? Typically there is a single person which signs the bill into a law. But there is collaboration during work on the bill, though.
But I do not think that people who make laws want to write git commands in the console. They want the GUI (ideally integrated into Microsoft Word). And if we are making GUI why not drop git and use a traditional relational database for storing the data?
Git is useful for a single person, too.
You are right that the default UI of git is intimidating for normal people.
Saying 'relational database' says about as much about how you actually store the data as saying 'json' or 'xml'. Yes, you could use a variant of git that stores all its information in a relation database. (And in a saner parallel universe, git might have used something like sqlite internally, instead of hand-rolling its own formats from scratch.)
But the question of UI is pretty much independent from the question of how you want to store the data.