docs: add node npm setup note

[Mohit-001-hash]

🔀 Pull Request

📌 Issue Reference

Closes #None (just a documentation quick fix)

---

📝 Summary

• Added a small note to the setup instructions.
• Clarified that Node.js and npm should be installed and available in the system PATH before running npm install.

---

📸 Screenshots (if applicable)

Not applicable — documentation-only change.

---

✅ Checklist

• My code follows the project's coding conventions
• I have tested all impacted features
• I have updated or added necessary documentation

---

🏅 Open Source Program Participation

Program Name: GSSoC 2026

---

💬 Additional Notes

Documentation-only change with no application code modifications.

[vercel]

@Mohit-001-hash is attempting to deploy a commit to the Sufal Basak's projects Team on Vercel.

A member of the Team first needs to authorize it.