docs: fix grammar errors in README.md

[cairon-ab]

Description

Fixes two grammar errors in README.md:

1. "has rewrote" → "has rewritten" — incorrect past participle (Warning box about old Model API)
2. "which is an parsed" → "which is a parsed" — incorrect article (description of parse() return value)

No functional changes.

[changeset-bot]

⚠️ No Changeset found

Latest commit: 56b9028

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[cairon-ab]

Hi team 👋 — this PR has been open for about 9 days and has one approval from @princerajpoot20. All CI checks are passing. Could another maintainer take a quick look when you get a chance? It's a small grammar fix in the README. Thank you!