Use versioned links for online v5 docs

[fflaten]

PR Summary

Updates website links to use versioned URLs to make sure they don't break when v6 is released.

Fix #2503

⚠️ Pending this PR for new links to work:

• pester/docs#316

PR Checklist

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• [ ] Tests are added/update (if required)
• [x] Documentation is updated/added (if required)