Backport of docs - address feedback on service mesh overview for k8s into release/1.14.x

[hc-github-team-consul-core]

Backport

This PR is auto-generated from #18045 to be assessed for backporting due to the inclusion of the label backport/1.14.

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The person who merged in the original PR is:
@david-yu
This person should manually cherry-pick the original PR into a new backport PR,
and close this one when the manual backport PR is merged in.

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

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Description

Address feedback from #18037

Testing & Reproduction steps

Links

PR Checklist

• updated test coverage
• external facing docs updated
• appropriate backport labels added
• not a security concern

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Overview of commits

• a74a792

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[github-team-consul-core-pr-approver]

Auto approved Consul Bot automated PR

[david-yu]

Will close and incorporate into other backported PRs.