I had this idea over 10 years ago but never finished it. I hope this takes off. I do fear it's not very practical for many big pieces of legislation which are often written in secret.
Likewise, a younger, more idealistic me thought it'd be great to use a GitHub-esque platform for laws. Pull Requests to suggest laws, gated behind reviews/approvals, branches so each house could work on their own versions before finally reconciling and merging into the Code, literally.
Don't worry about that. Even if we only saw voted-upon revisions in the Git history, it will still be a huge improvement.
Version control for the public parts will make both public and secretive law-drafting better.