Fix valid, but failing GH project link for #1620.

[aj-stein-nist]

Committer Notes

Fix valid, but failing GH project link for #1620. This link failure blocked the proper deployment of website content to #1614 after merge regarding new public calendars.

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[aj-stein-nist]

I missed one of the problematic links, but this is ready for review, @david-waltermire-nist.