Looking at this neat little project I was a bit surprised that it needed a full (OR)DBMS.

I love PostgreSQL, but sometimes for small, self-contained projects I think that SQLite is (perhaps) a wise choice - especially when it's going to often be run in Docker containers for local use as it saves having to pull down a full PostgreSQL Docker image and run a container for it.

If it's not worth the effort feel free to reject the suggestion :)