Update about-keys-secrets-certificates.md

[LucasLeitao-MSFT]

Keys, Secrets and Certificates can have their name starting with numbers (1-9) or with '-'. Adjusting doc to be compliant with the current experience.

Example:

[prmerger-automator[bot]]

@LucasLeitao-MSFT : Thanks for your contribution! The author(s) have been notified to review your proposed change.

[learn-build-service-prod[bot]]

Learn Build status updates of commit 9045e91:

:white_check_mark: Validation status: passed

File	Status	Preview URL	Details
articles/key-vault/general/about-keys-secrets-certificates.md	:white_check_mark:Succeeded

For more details, please refer to the build report.

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[Court72]

@msmbaldwin

Can you review the proposed changes?

When the changes are ready for publication, add a #sign-off comment to signal that the PR is ready for the review team to merge.

#label:"aq-pr-triaged" @MicrosoftDocs/public-repo-pr-review-team

[PMEds28]

@msmbaldwin

Can you review this old PR and determine whether it needs to be closed or merged?

IMPORTANT: When the changes are ready for publication, add a #sign-off comment to signal that the PR is ready for the review team to merge. If the changes no longer apply, add an explanation and a #please-close comment to close the PR.

@MicrosoftDocs/public-repo-pr-review-team

[JamesJBarnett]

I sent email to the content owner today.

@MicrosoftDocs/public-repo-pr-review-team

[msmbaldwin]

Hi @LucasLeitao-MSFT, and thanks for calling this to our attention. My own testing verifies your observation. We appreciate your help in improving our documentation! #sign-off