Exporting `usePDFDocument` hook.

[chopfitzroy]

Can totally understand the concerns raised in #3 in regards to exposing all hooks.

I have a use case that could really benefit from having access to the PDFDocumentProxy would you be opposed to a PR exporting the usePDFDocument hook?

Happy to try and write up some docs for the Storybook as well if that helps.

[Titou325]

Hi!

That would be a welcome addition indeed, at least outlining the possible edge cases.

Thanks!