misc: add polarify usecase as an example

[ruben-arts]

Add the polarify example from the design document to the examples.
Tested on:

• linux-64
• osx-arm64
• win-64

[baszalmstra]

win-64

✨ Pixi task: python -c "import sys; print(f\"Python version: {sys.version}\"); import polars; print(f\"Polars version: {polars.__version__}\")"
Python version: 3.12.1 | packaged by conda-forge | (main, Dec 23 2023, 07:53:56) [MSC v.1937 64 bit (AMD64)]
Polars version: 0.20.6

[nichmor]

osx-arm64

✨ Pixi task: python -c "import sys; print(f\"Python version: {sys.version}\"); import polars; print(f\"Polars version: {polars.__version__}\")"
Python version: 3.12.1 | packaged by conda-forge | (main, Dec 23 2023, 08:01:35) [Clang 16.0.6 ]
Polars version: 0.20.6