WIP: Implement property schema validation

[crunchie84]

Fixes #73

TODOS

• [x] document schema
• [x] manually verify JSON schema (https://www.jsonschemavalidator.net/)[https://www.jsonschemavalidator.net/]
• [x] Verify that unit tests still run
  • I didn't see an easy way to add unit tests for the json schema 🤔
• [ ] Test that when using this version of the plugin the console warning is no longer rendered
  • If the maintainer of this repo easily can do the test that would be really great, need to figure out how to link a local version of a plugin into my codebase