Missing documentation for interfaces like FormikConfig in https://formik.org/docs

## Feature request

### Current Behavior

example: https://formik.org/docs/api/useFormik

No paths to dive into the interfaces.

### Desired Behavior / Suggested Solution

Have pages and ways to dive into the interfaces in docs

### Who does this impact? Who is this for?

Reviewer of projects using this library. Not so much affecting developers, but important.

### Describe alternatives you've considered

N/A

### Additional context

I'm currently referring to them through opening GitHub codespace to search `FormikConfig`

Start with the Formik documentation page for useFormik at https://formik.org/docs/api/useFormik and inspect how its referenced interfaces are presented. Search the repository for FormikConfig and the documentation entry points to understand the existing navigation. Done means users can reach pages describing the relevant interfaces from the API documentation.

Written by the indexing model from the issue text.