Consistent source of ontological data - default_base_models.json

AtomicData.dev classes and properties live in various places:

• On AtomicData.dev (the server), stored in the KV store of that instance
• In populate::populate_base_models, which is used for populating the base models (to prevent infinite loop on hosting atomicdata.dev, see #60). This contains only a small number of properties - only these needed to parse default_store.json.
• In default_store.json, containing most classes and properties.
• default_base_models.json, which should contain the same properties as populate_base_models. I think we should remove this one.

This causes a few problems:

• Whenever we create / update a Property or Class, we probably want to update the live version on atomicdata.dev using the GUI. That's the easiest, and it can instantly be used during development. This means that we have to update the default_store.json after that. If we forget to do this, the .json becomes outdated.
• Contributors may update default_base_models.json without updating populate.rs

Solutions:

• Remove default_base_models.json
• Add a CONTRIBUTING.MD section on updating ontological data
• Come up with a way to generate JSON-AD from atomicdata.dev. Export / serialize from ontology level?

Start by comparing default_base_models.json, default_store.json, and populate.rs, especially populate::populate_base_models, to identify overlapping ontological data and how each file is used. Review the issue's proposed CONTRIBUTING.MD guidance and the handling of data on atomicdata.dev; done means the source of ontological data is consistent and contributors have clear update instructions.