[DOC] Search backpressure SearchTask cancellation documentation

[PritLadani]

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.
As a part of opensearch-project/OpenSearch#5173, we have introduced SearchTask cancellation based on resource consumption. We need to update the public documentation to add the response when a query is cancelled due SearchTask cancellation.

What other resources are available? Provide links to related issues, POCs, steps for testing, etc.
Issue link: opensearch-project/OpenSearch#5173
PR: opensearch-project/OpenSearch#5605
Current public doc: https://opensearch.org/docs/latest/opensearch/search-backpressure#search-backpressure-settings
Previous doc update link: #2629

[kolchfa-aws]

@PritLadani Could you specify what needs to be added please?

[PritLadani]

@kolchfa-aws I am waiting for this PR opensearch-project/OpenSearch#6634 to get merged. Once that is done, we update the documentation.
Will update the PR probably next week.