docs: improve README wording

[Rohan5commit]

Summary

• improve one README sentence by adding the missing article before "ones"

Related issue

• N/A (trivial docs wording fix)

Guideline alignment

• CONTRIBUTING: none found in the repo root or .github on main
• PR template: none found in the repo root or .github on main

Validation

• Not run (docs-only change)

[Copilot]

Pull request overview

This PR makes a small wording improvement in the README’s pMap API description to improve readability and grammatical correctness.

Changes:

• Update the pMap description sentence to include the missing article (“the ones”) for clearer phrasing.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.