Exports are wrongly typed with module node16

Due to `export default ...` the types announce a named export called "default", which indeed does not exist necessitating the following workaround:

```ts
import ajvTransformKeywordBorkedDefault from "ajv-keywords/dist/definitions/transform.js"

// moduleResolution: node16 workaround, the types erroneously have a named export "default" on the default export
const ajvTransformKeyword =
ajvTransformKeywordBorkedDefault as unknown as typeof ajvTransformKeywordBorkedDefault.default
```

See similar issue https://github.com/ajv-validator/ajv/issues/2132, but at least on ajv-validator the types and what is actually exported by the compiled JS still agree.