Backport of added redirect for conf entries 1.8.x into release/1.15.x

[hc-github-team-consul-core]

Backport

This PR is auto-generated from #19460 to be assessed for backporting due to the inclusion of the label backport/1.15.

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The person who merged in the original PR is:
@trujillo-adam
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.

merge conflict error: POST https://api.github.com/repos/hashicorp/consul/merges: 409 Merge conflict []

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

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Description

Prior to v1.9.x, configuration entries appeared int he /agent dir instead the /connect dir. This PR redirects people who view a conf entry in the current /connect folder and switch to docs v1.8.x so that they land on the conf entry in the /agent folder. Fixes per this Slack thread.

PR Checklist

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

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Overview of commits

• 21f193c

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• trujillo-adam
• temp

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

Auto approved Consul Bot automated PR