feat: Migrate play notebook to Python script and update dependencies

- Removed the `play.ipynb` notebook and created a new `playground.py` script to enhance code organization and maintainability.
- Updated `pyproject.toml` to include `jupytext` for Jupyter notebook conversion support.
- Added instructions in `README.md` for converting notebooks using Jupytext.
- Enhanced the `uv.lock` file to reflect the new dependency on Jupytext.

README.md

@@ -0,0 +1,4 @@
+
+```bash
+jupytext --to py:percent <script>.ipynb
+```