chore: add JSON schema for `netlify.toml`

[danez]

Summary

This PR adds a new JSON schema file for netlify.toml. A direct link to this file will be added to https://github.com/SchemaStore/schemastore. Most IDEs (vscode with extension, intellij) try to read schemas from this store.

In the future, the schema could even be used to validate the netlify.toml file in @netlify/config, as I saw right now we have some hardcoded validation in the code.

The new package is private for now, so even if we want to rename it later into maybe config-validation we can simply do this.

I added docs as reviewer, because I added a lot of links pointing to the docs and also copied most of the text from the docs.

Ref: https://github.com/netlify/pod-compute/issues/138

A picture of a cute animal (not mandatory, but encouraged)

[lukasholzer]

@danez any updates on this one? Would love having autocompletion for the toml 😂

[github-actions[bot]]

~This pull request adds or modifies JavaScript (.js, .cjs, .mjs) files. Consider converting them to TypeScript.~ Thank you for converting JavaScript files to TypeScript 🎉"

[danez]

and the functions field on the build settings

The docs though say it should be this:

[functions]
  directory = "my_functions"

maybe [build] -> functions is the old way of doing it?

[lukasholzer]

and the functions field on the build settings

The docs though say it should be this:

[functions]
  directory = "my_functions"

maybe [build] -> functions is the old way of doing it?

mhm maybe @eduardoboucas can put some light on that?

[danez]

and the functions field on the build settings

The docs though say it should be this:

[functions]
  directory = "my_functions"

maybe [build] -> functions is the old way of doing it?

Looks like it was an older version of the config: https://github.com/netlify/build/blob/f1d8ebc03b95d1e614ce64ad4083c3f7eb420c7b/packages/config/src/functions_config.js#L12

I added it as deprecated.

[danez]

I solved all the review comments. I had to rebase because of conflicts, but all new changes are in separate new commits. starting with chore: add test for cache

[danez]

The config for edge functions is currently incorrect in the schema:

• excludePattern, excludePath and pattern are missing from the schema
• path is currently only allowed to be a string, but it can also be an array of strings