Provide PDFDownloadLink some sort of prop that supports lazy or conditional loading?

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Hey everyone, first off I want to say that this package is really impressive, thanks for maintaining it. Also, if going to go off on assumptions regarding this feature, so excuse me if I got anything wrong. Now on topic, I've noticed that, as expected, generating PDF files is a costly operation, performance wise. So during render, a lot of files are fetched and since my generated PDF is dynamic, the performance takes a hit due to every re-render. To optimize this behavior I currently have to do workarounds from an upper scope of the `PDFDownloadLink` component, for example.

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Either delay or debounce the initial PDF generation. I think an awesome feature would be to wait X amount of seconds until the PDF should start to load, and if there is a re-render or a change in the passed props to the document prop of the `PDFDownloadLink` component, then simply hold it off and/or restart the timer. Basically, debounce.

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As I mentioned earlier, either debouncing it or delaying it. I guess throttling might work fine as well but throttling doesn't seem appropriate for this use-case. Passing a `shouldLoad` prop would work wonders too, but it would require external logic on an upper scope.