Very amoosing. The cherry on top is that the backend is in Rust.

Rust is insufficiently bovine-themed. The backend should be rewritten in COW language: https://bigzaphod.github.io/COW/

I know robots.txt, I know humans.txt. But I don't get cow.txt after reading the website.

It's a chain mail for server admins.

I think it's a bit of a joke and nothing else