Backport of Add Service Discovery Use Case into release/1.13.x

[hc-github-team-consul-core]

Backport

This PR is auto-generated from #14066 to be assessed for backporting due to the inclusion of the label backport/1.13.

WARNING automatic cherry-pick of commits failed. Commits will require human attention.

The below text is copied from the body of the original PR.

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Description

This page is being created to add high level service discovery information to the docs.

Links

Asana Task: https://app.asana.com/0/708546246086263/1201846609169222/f Google Doc: https://docs.google.com/document/d/1VJXRmOIbSezbIxfXfaiLixLHd7XPYqIk6iv_JSgHGPM/edit

PR Checklist

• [ ] updated test coverage
• [x] external facing docs updated
• [x] not a security concern

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[david-yu]

No-op PR