Adding new cluster search setting docs

[harshavamsi]

Description

Adds docs around new cluster search setting

Issues Resolved

Resolves #8175

Version

2.17

Frontend features

If you're submitting documentation for an OpenSearch Dashboards feature, add a video that shows how a user will interact with the UI step by step. A voiceover is optional.

Checklist

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[github-actions]

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[kolchfa-aws]

Thank you, @harshavamsi! We want to avoid Java class names in documentation and just explain what the term means. Could you please clarify what is meant by "index or doc_values query"?

[harshavamsi]

@kolchfa-aws IndexOrDocValuesQuery essentially will make a decision during query time to decide whether to use the index structure to run the query or the doc_values. It comes from Apache Lucene, I wasn't sure how we could better describe here since it really is an implementation detail and the class name is as verbose as it gets.

[kolchfa-aws]

Thank you! I updated my suggestion.

[kolchfa-aws]

Thank you, @harshavamsi! LGTM

[natebower]

LGTM