Feature request: Add types for TypeScript

[tyankatsu0105]

I want to use the eslint-utils with TypeScript. However, the project doesn't have types.

typescript-eslint and eslint-plugin-vue has type themselves.

How about having type for developers who want to use TypeScript?

[mysticatea]

Sounds nice idea.

But I'm worried about AST node types. Each third-party parser has additional nodes. If this package has AST types, does it cause type errors about the additional nodes?

[ota-meshi]

FYI DefinitelyTyped/DefinitelyTyped#53803

[JoshuaKGoldberg]

@mysticatea this issue can be closed, I think.