foundry verify guide added

[ayo-klaytn]

✨ Proposed Changes

Foundry Verify guide added.

🗂️ Types of changes

• Minor Issues and Typos
• Major Content Contribution
• Others (e.g. platform-specific changes)

🔒 CLA requirements - FIRST-TIME CONTRIBUTORS only 📝

Welcome! Before we can review your PR, there's one important step:

1. Read our Contributor License Agreement.
2. Sign by commenting exactly this in the PR: I have read the CLA Document and I hereby sign the CLA

🔍 Why This Matters: This protects both you and the project, ensuring everyone can safely use your contributions. Without CLA signing, we can't merge your PR. Thank you for your understanding!

✅ Checklist

• I have read the CONTRIBUTING GUIDELINES.
• I have added necessary documentation (if appropriate).
• Any dependent changes have been merged and published in downstream modules.

📌 Related issues

💡 Further comments