JSON schema syntax

[swo]

Content of the change

• Everything is a JSON object! At the cost of R0: {fix: 1.5}, you get so much simplicity and modularity:
  • a top-level version
  • each parameter stands on its own
  • each syntax around varying bundles of parameters and conditioned parameters
• Use https://json-schema.org/ to write the griddler schema
  • Use pytest to check that I wrote the schema correctly

To do

• Describe a v0.3 syntax
• Get feedback
• Allow for versioning
• Consider using https://json-schema.org/
• Add runtime validation (for things that the schema validation can't check for)
• Implement & test
• Update README and other docs

[swo]

@bbbruce Thanks for having a look! I'm hoping to make this clearer (the nested grids were not clear) while keeping the good ergonomics.

[bbbruce]

Yes @swo I don't think I made an overall comment that this really looks like a move in a great direction to me!