Very clever. I would be concerned however that GitHub may shut you down at some point and if this got serious it would have to be running on federated git servers and then you would need a secure synchronization protocol Etc pretty soon you're looking at Matrix
A few months ago I started playing with using Matrix as a janky social media replacement. The idea was to setup a space with rooms that I post in. One room might be a public, unencrypted room that anyone can read (ala Twitter/Mastadon/etc), and another might be just for close friends, etc. Then, I just post to them like you would on any other platform.
It's great because it's the only platform like this where you have the ability to encrypt if you want to, but it is of course missing some features. The biggest being the ability to share posts and have a meta feed. There are also smaller annoyances that would not scale well, such as the fact that people cannot make personal room name aliases.
