Update CLI help message to match documentation

[emmatown]

#5425 (comment)

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🦋 Changeset detected

Latest commit: 6e401f7

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 4 packages

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@keystone-next/keystone	Patch
@keystone-next/test-utils-legacy	Patch

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[timleslie]

Thanks 🙏

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