Support for List[A]

This is a feature request.
Some forms have options to add/subtract List of items. For example:- List[Pet]

The implementation will be whenever List[A] is encountered:
- Add and Subtract Button should appear, doing their respective job.
- Form Label should add `n` for nth display of list item
- Validation should also work with `nth` context and error reporting.

I am very much inclined to develop it, if this request makes sense to you.
Thanks

Begin by examining the repository's form implementation and validation/error-reporting paths, then trace how a List[A] value would be represented. Done means list fields support add and subtract controls, labels identify each item with its position, and validation reports errors in the correct nth context.

Written by the indexing model from the issue text.