Provide guidance on how users should be doing "freshness" checks on install scripts

[richlander]

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We would like to be able to write a test that validates if our CDN copy matches repo copy. I know that GitHub Actions does this as well. This would help ensure that users only pickup up copies that we have high confidence in and only feel compelled to update their script at (no more than) a monthly cadence. Basing that all off of main seems like not the best model.