[DOC] Update documentation for Using Search Pipeline

[owaiskazi19]

What do you want to do?

• Request a change to existing documentation
• Add new documentation
• Report a technical problem with the documentation
• Other

Tell us about your request. Provide a summary of the request and all versions that are affected.
Search Pipeline will support default pipeline for multiple indices in 2.14.
Issue: opensearch-project/OpenSearch#7512
PR: opensearch-project/OpenSearch#13276

What other resources are available? Provide links to related issues, POCs, steps for testing, etc.

[minalsha]

@owaiskazi19 is the POC. @hdhalter requesting support for documentation for this enhancement. Thanks

[hdhalter]

Thanks, @owaiskazi19 !