Include frozenset in tutorial

[theo-brown]

The tutorial section on 'Extra Data Types' did not include an example of frozenset.

[tiangolo]

Thanks for the interest and effort! :nerd_face:

I wasn't trying to include all the possible data types supported by Pydantic.

But still, I'm curious, in which cases do you think a frozen set would be required or particularly useful?

I haven't found a use case where I need it, also that justifies explaining it in the docs. :shrug:

Sorry for the long delay! 🙈 I wanted to personally address each issue/PR and they piled up through time, but now I'm checking each one in order.

[github-actions[bot]]

Assuming the original need was handled, this will be automatically closed now. But feel free to add more comments or create new issues or PRs.