Improved the documentation for cat indices API

[mridula-s109]

Summary

• clarify the _cat/indices documentation to state that docs.count is taken directly from Lucene
• note that this includes hidden nested documents (including those created by semantic_text)
• point readers to _cat/count and _count when they need the logical/top-level document count instead

Github issue - #127354

[elasticsearchmachine]

Pinging @elastic/search-relevance (Team:Search - Relevance)

[elasticsearchmachine]

Pinging @elastic/core-docs (Team:Docs)

[leemthompo]

Hey @mridula-s109! I think we need to make these changes in the elasticsearch-specification repo.

The file would be https://github.com/elastic/elasticsearch-specification/blob/main/specification/cat/indices/CatIndicesRequest.ts#L25

• There's a lot of moving parts, if you're interested there's some overview information about how all the pieces fit together here: https://www.elastic.co/docs/contribute-docs/api-docs/overview#example-elasticsearch
• See the quickstart to help you work and generate a preview locally.

[mridula-s109]

Hey @mridula-s109! I think we need to make these changes in the elasticsearch-specification repo.

The file would be https://github.com/elastic/elasticsearch-specification/blob/main/specification/cat/indices/CatIndicesRequest.ts#L25

• There's a lot of moving parts, if you're interested there's some overview information about how all the pieces fit together here: https://www.elastic.co/docs/contribute-docs/api-docs/overview#example-elasticsearch
• See the quickstart to help you work and generate a preview locally.

@leemthompo thanks for the guidance. i will have a look at it and create a new PR.