Missing config schema.

We really need to land this, ideally in a tagged release; it's needed for Drupal CMS.

And not only in Drupal CMS, as now config validation is adopted more and more in core, it is important to have the schema, so that validation can do its job properly.

Confirming that the patch works with recipe config actions too.

Action that was tested:

config:
  actions:
    node.type.*:
      setThirdPartySetting:
        module: search_api_exclude
        key: enabled
        value: 1

Automatically closed - issue fixed for 2 weeks with no activity.