Add intro-to-notion-api example for Python SDK

[Sumeet213]

#278

Summary

Adds intro_to_notion_api example directory for the Python SDK, mirroring the structure and functionality of the JavaScript SDK's
intro-to-notion-api example.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.51%. Comparing base (efccd0f) to head (90882e9).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #297   +/-   ##
=======================================
  Coverage   99.51%   99.51%           
=======================================
  Files           7        7           
  Lines         409      409           
=======================================
  Hits          407      407           
  Misses          2        2           

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[ramnes]

Thanks for this PR!

That CI error is curious, but that's most likely unrelated to your changes here so I'll go ahead and ignore it.