[Doc] Update bulk descriptions

[Naarcha-AWS]

Description

This PR updates description for the Bulk schema, used in the Bulk API.

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[github-actions]

Changes Analysis

Commit SHA: f3ee2f4
Comparing To SHA: 9771b03

API Changes

Summary

└─┬Components
  ├─┬_core.bulk:ResponseItem
  │ └─┬_index
  │   └──[🔀] description (40875:24)
  ├─┬_core.bulk:WriteOperation
  │ └─┬ALLOF
  │   ├─┬require_alias
  │   │ └──[🔀] description (40961:28)
  │   ├─┬pipeline
  │   │ └──[🔀] description (40955:28)
  │   └─┬dynamic_templates
  │     └──[🔀] description (40947:28)
  ├─┬_core.bulk:UpdateAction
  │ ├─┬detect_noop
  │ │ └──[🔀] description (40909:24)
  │ ├─┬doc_as_upsert
  │ │ └──[🔀] description (40917:24)
  │ └─┬scripted_upsert
  │   └──[🔀] description (40922:24)
  └─┬_core.bulk:UpdateOperation
    └─┬ALLOF
      └─┬require_alias
        └──[🔀] description (40937:28)

Document Element	Total Changes	Breaking Changes
components	8	0

• Total Changes: 8
• Modifications: 8

Report

The full API changes report is available at: https://github.com/opensearch-project/opensearch-api-specification/actions/runs/11131299228/artifacts/2002377485

API Coverage

	Before	After	Δ
Covered (%)	588 (57.59 %)	588 (57.59 %)	0 (0 %)
Uncovered (%)	433 (42.41 %)	433 (42.41 %)	0 (0 %)
Unknown	29	29	0

[github-actions]

Spec Test Coverage Analysis

Total	Tested
504	303 (60.12 %)

[dblock]

I think the schema supports default: false, when editing text you can add those too.