Add rounding instructions to disclosure docs

[LFISHER7]

This could be expanded on in the future, but provides at least some instruction for rounding.

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[StevenMaude]

suggestion: Would it be useful to have a concrete example with fictitious data? This could show tables before and after the redaction and rounding process.

This might help illuminate the details, in case a reader either misinterprets the instructions or is otherwise unclear on the meaning.

It's possible to add simple tables in the Markdown without too much work.

[StevenMaude]

Otherwise, the text looks fine. But better for someone who knows our disclosure controls well to approve it 🔍

[LFISHER7]

Thanks @StevenMaude , that's a good suggestion, I'll get something added

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[Jongmassey]

Both the text and example are excellent, and I look forward to referring researchers to this in future!