"PostgREST is a standalone web server that turns your PostgreSQL database directly into a RESTful API. The structural constraints and permissions in the database determine the API endpoints and operations."
If that shows what it does, than this project has no point at all, because REST is about a lot of things, but tying your database schema directly to your API is not one of them.
One of the main point of REST is that it abstracts away the implementation detail of your project, so the client don't need to know anything about your database, they can use the things you expose them via the API.
It's really sad that there are 54 developers who can't see this and made a useless thing instead of doing something great with their time.
I'm never against somebody doing something, I usually really sorry that talent, time and hard work get wasted so much on unnecessary things.