Add web app deployment slots to private-endpoint-dns.md

[Mike-Nahmias]

Adding private endpoint details for (Microsoft.Web/sites/slots)

[prmerger-automator]

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

[learn-build-service-prod]

Learn Build status updates of commit 283bd5d:

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File	Status	Preview URL	Details
articles/private-link/private-endpoint-dns.md	✅Succeeded

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[ttorble]

@AbdullahBell

Can you review the proposed changes?

IMPORTANT: When the changes are ready for publication, adding a #sign-off comment is the best way to signal that the PR is ready for the review team to merge.

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

[PMEds28]

I sent an email to the content owner today.

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

[ttorble]

I sent a Teams message to the content owner today.

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

[AbdullahBell]

Hello, thank you for your contribution to the docs! This PR is under review

[v-ccolin]

I sent an email to the content owner today.

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

[ttorble]

I sent a Teams message to the content owner today.

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