Accessing Validator-helper class from custom rule definition

When creating a custom rule, it would be helpful to be able to use the Validator helper-class from src/meta/validate.ts - just like built-in rules like e.g. src/rules/element-permitted-content.ts.

Use cases

I've built a plugin with a custom rule for restricting the permitted text-content within nodes. One part of the rule-configuration is setting which categories to apply to rule to. This is implemented using Validator.validatePermittedCategory().

This was first built against an old version of html-validate (1.16), where I could access the Validator-class from the general meta-exports via require("html-validate/build/meta");.

However, in the current version of html-validate, there is no export of either the meta-namespace or a more specific export of the Validator-class.

As far as I can tell, that makes it impossible to use the Validator-helper-class from the distributed versions of html-validate.

I would love to have the Validator-class exported in the builds so I can upgrade my plugin to the later versions of html-validate.