WIP: Working on underlying libraries using TDD for now :)

Provide a mode for codemirror 6 that:

1. lints: validates json strings with positional information, for parsing errors and json schema errors
2. hints: provides code completion for json schema
3. infos: provides hover info for json schema
4. It leverages$schema path url if provided in the JSON string, or a json schema that is provided to the mode API, preferring the former.

monaco-json and monaco-yaml both provide these features, and I want the nascent codemirror 6 to have them as well!

• working GeoJSON spec linter & completion
• working variables json mode for cm6-graphql, ala monaco-graphql