feat: add pharmacy-locator-agent using free Overpass API

[geo-guy07]

Summary

This PR introduces the Pharmacy Locator Agent, a beginner-friendly agent that takes natural language location queries (parsed by ASI:One) and fetches real-world pharmacy coordinates/data using the free OpenStreetMap Overpass API. This provides a zero-friction example for healthcare/geolocation verticals without requiring any paid API keys.

Type of Change

[✅] New agent example

• Bug fix
• Documentation update
• Refactor / cleanup
• Other

Checklist

• [✅] I have starred this repository.
• [✅] I ran ruff check ..
• [✅] I ran ruff format ..
• [✅] I added/updated README.md for changed example(s).
• [✅] I added .env.example if environment variables are required.
• [✅] I added demo image/GIF (if applicable).
• I added agent profile link (if applicable).
• [✅] I updated CHANGELOG.md (required for non-doc changes).
• [✅] I verified paths/commands used in docs.

Related Issue

Closes #46

Notes for Reviewers

1. I have included a test script (test_agent.py) so reviewers can instantly test the agent logic locally without needing to set up external endpoints.
2. The Overpass API integration uses the httpx module with the required User-Agent and Accept headers to prevent 406 rejections.
3. Included python-dotenv and explicit event loop creation in agent.py to ensure compatibility with Python 3.13 users.
4. "I hardcoded the test_agent.py script to query 'London' to guarantee consistent output for the demo screenshot, but the agent.py logic itself dynamically works for any globally recognized city/neighborhood name in OpenStreetMap."

[geo-guy07]

hello @gautammanak1 any issue with this ???