[docs] Pandas to Polars
Sorry for the wait! This PR updates the current code examples in the Parquet [docs](https://huggingface.co/docs/datasets-server/parquet) to use Polars instead of Pandas. It also switches out the `alexandriainst/danish-wit` with the `amazon_polarity` dataset because it returned an error saying conversion is limited to datasets under 5GB.

I'll follow this up with another PR for the new Parquet guide (querying/use in web apps with duckdb) 🙂
[docs] Pandas to Polars: Sorry for the wait! This PR updates the current code examples in the Parquet [docs](https://huggingface.co/docs/datasets-server/parquet) to use Polars instead of Pandas. It also switches out the `alexandriainst/danish-wit` with the `amazon_polarity` dataset because it returned an error saying conversion is limited to datasets under 5GB.

I'll follow this up with another PR for the new Parquet guide (querying/use in web apps with duckdb) 🙂