Define minimal schema via relationships/edges

[nathanclevenger]

I want this to be a YAML-based file format ... but we should define the interface in typescript, and then use https://github.com/YousefED/typescript-json-schema to generate JSON schema ... then we should publish the JSON schema in the Schema Store https://www.schemastore.org/json/ and configure it with a specific naming convention that will then auto detect and support intellisense in VSCode and other editors