Add description for level parameter in cluster health.

[Naarcha-AWS]

This adds a description for the level parameter in the cluster health API. This helps it appear in the table.

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[github-actions]

Changes Analysis

Commit SHA: 07ebad0
Comparing To SHA: 22483a2

API Changes

Summary

├─┬Paths
│ ├─┬/_cluster/health/{index}
│ │ └─┬GET
│ │   └──Parameters
│ └─┬/_cluster/health
│   └─┬GET
│     └──Parameters
└─┬Components
  └─┬cluster.health___Level
    └──[➕] description (50257:20)

Document Element	Total Changes	Breaking Changes
paths	0	0
components	1	0

• Total Changes: 1
• Additions: 1

Report

The full API changes report is available at: https://github.com/opensearch-project/opensearch-api-specification/actions/runs/13333767897/artifacts/2593924699

API Coverage

	Before	After	Δ
Covered (%)	663 (64.94 %)	663 (64.94 %)	0 (0 %)
Uncovered (%)	358 (35.06 %)	358 (35.06 %)	0 (0 %)
Unknown	45	45	0

[github-actions]

Spec Test Coverage Analysis

Total	Tested
595	593 (99.66 %)