Adds documentation for providing search pipeline id in the search/msearch request

[owaiskazi19]

Description

Added support for msearch API to pass search pipeline name.
With this change a search pipeline name can be provided while making a msearch call

{ "index": "test"}
{ "query": { "match_all": {} }, "from": 0, "size": 10, "search_pipeline": "my_pipeline"}
{ "index": "test-1", "search_type": "dfs_query_then_fetch"}
{ "query": { "match_all": {} }, "search_pipeline": "my_pipeline1" }

Issues Resolved

opensearch-project/OpenSearch#15923

Version

2.18

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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[kolchfa-aws]

@owaiskazi19 Is this for 2.18?

[owaiskazi19]

@owaiskazi19 Is this for 2.18?

Yes @kolchfa-aws. Here is the backport PR opensearch-project/OpenSearch#16085. Once this gets merged it will be ready for 2.18

[epugh]

I don't know that this is a true "pattern", (and if it is we should have Vale enforce it), but in other places in the docs I see it referred to as "multi-search". For example I see "All multi-search URL parameters are optional.".

Suggested change

	or for msearch
	or for multi-search:

[kolchfa-aws]

Thank you, @owaiskazi19!

[natebower]

@owaiskazi19 @kolchfa-aws LGTM!