Create a schema for editors when modifying the config YAML

[lyricnz]

This would be useful for auto-completion, valid options, etc.

[lyricnz]

I generated a JSON schema from our Zod schema using https://github.com/StefanTerdell/zod-to-json-schema myschema.json

Then added a comment at the top of a config yaml file:

# yaml-language-server: $schema=myschema.json

Which gave me autocomplete, and warnings about missing mandatory fields!

[lyricnz]

See https://github.com/redhat-developer/yaml-language-server?tab=readme-ov-file#using-inlined-schema

[lyricnz]

This helps avoid errors, since the schema can point out invalid attributes.

Of course, @abukharov wants to be able to add random stuff to the YAML - so maybe there needs to be an option for that (or ignore the warnings)