docs: fix API description typos (#135)

[STATUS-Z]

Summary

Fixes documentation typos in the Population Density Data API OpenAPI description (#135).

Restored after mistaken fork handling (detached/orphan backup). Equivalent to the prior closed contribution.

Changes

• Grammar: "do not treat… neither" → "does not treat… as either"
• "Identify and Consent Management" → "Identity and Consent Management"
• Async callback sentence punctuation

Test plan

• Diff against code/API_definitions/population-density-data.yaml looks correct
• Spec still parses

[linux-foundation-easycla]

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[jgarciahospital]

Hi @STATUS-Z, thanks for submitting the PR. That's exactly the change we were looking for, but we've already addressed it in this PR: #141.

BTW, please take a look on your easyCLA status, as there seems to be an error.