Add stagehand

[charlypoly]

Project

stagehand

Checklist

• I read CONTRIBUTING.md - awesome-python is a shortlist, not a catalog
• One project per PR
• PR title format: Add project-name
• Entry format: - [pypi-name](https://github.com/owner/repo) - Description ending with period.
• Display name is the PyPI package name
• Placed in an existing use case (new sections and subcategories are maintainer-only)
• Meets all Quality Requirements: active, stable, documented, at least 1 month old

Which Tier

Pick one:

• Obvious choice - a tool an experienced Python developer would name when asked "what do I use for this?"
• Challenger - not yet the obvious choice, but a credible successor to one. Give adoption-trajectory evidence, not popularity alone.

Explain:
We created Stagehand 2 years ago as a built-in replacement for Playwright for non-QA/testing use cases.
Stagehand is available in TypeScript (4 M monthly downloads), Python (1M monthly downloads), and Go under an MIT license with full support for local browsers.

A month ago, we rewrote our Python SDK completely for a better developer experience (idiomatic), and we keep saying our usage among Python developers is increasing. Beyond open-source usage, Stagehand is using by thousands of companies in production.