JSON schema for config files

[niklasravnsborg]

Having schemas for the Helix config files (config.toml, some_theme.toml, languages.toml) would be highly beneficial. This would not only facilitate easier editing of configurations but could also enable auto-generation of documentation tables or other useful outputs.

Schemas can be integrated using the $schema key to enable editor completions:

"$schema" = 'https://example.org/schema.json'

For reference, here are a few example schema files:

• Starship: https://starship.rs/config-schema.json
• Yazi: https://raw.githubusercontent.com/yazi-rs/schemas/main/schemas/yazi.json
• Alacritty: https://raw.githubusercontent.com/distinction-dev/alacritty-schema/main/alacritty/reference.json

Resources for creating a schema:

• Writing a schema
• Adding a schema to JSON Schema Store

[the-mikedavis]

Duplicate of https://github.com/helix-editor/helix/issues/3901, also see https://github.com/helix-editor/helix/pull/8644