> If I were to do this again, I would probably use a well-defined language like yaml or json to store object information.

I know this is only meant to be an educational project, but please avoid yaml (especially for anything generated). It may be a superset of json, but that should strongly suggest that json is enough.

I am aware I'm making a decade old complaint now, but we already have such an absurd mess with every tool that decided to prefer yaml (docker/k8s, swagger, etc.) and it never got any better. Let's not make that mistake again.

People just learned to cope or avoid yaml where they can, and luckily these are such widely used tools that we have plenty of boilerplate examples to cheat from. A new tool lacking docs or examples that only accepts yaml would be anywhere from mildly frustrating to borderline unusable.