feat(API): improve delete /projects/{project_id}/keys/{id}/key_links/{child_key_id} documentation

[Stephen Lumenta (sbl)]

Improves the documentation for delete /projects/{project_id}/keys/{id}/key_links/{child_key_id}: sharper descriptions, parameter docs, error responses, and usage examples.

Drafted with AI assistance and grounded in the API implementation. Please review for technical accuracy before merging; nothing is merged automatically.

🤖 Generated with Claude Code

[github-actions]

API changelog (oasdiff)

Doc-only edits (descriptions, examples) do not appear here.

4 changes: 0 error, 3 warning, 1 info
warning	[optional-response-header-removed] at doc/compiled.json
	in API DELETE /projects/{project_id}/keys/{id}/key_links/{child_key_id}
		the optional response header `x-rate-limit-limit` removed for the status `422`

warning	[optional-response-header-removed] at doc/compiled.json
	in API DELETE /projects/{project_id}/keys/{id}/key_links/{child_key_id}
		the optional response header `x-rate-limit-remaining` removed for the status `422`

warning	[optional-response-header-removed] at doc/compiled.json
	in API DELETE /projects/{project_id}/keys/{id}/key_links/{child_key_id}
		the optional response header `x-rate-limit-reset` removed for the status `422`

info	[response-optional-property-added] at doc/compiled.json
	in API DELETE /projects/{project_id}/keys/{id}/key_links/{child_key_id}
		added the optional property `errors/items/code` to the response with the `422` status