[TechDebt] Improve Getting Datasets Workflow

See https://github.com/TabArena/tabarena_benchmarking_examples/issues/5

I think we could easily add a function or example scripts on how to use the datasets w/o TabArena code to people who want to use them.
How exactly is to be determined.

Start by reading the linked tabarena_benchmarking_examples issue #5 and inspecting how this repository currently exposes dataset usage. The scope and implementation are explicitly undecided; done means providing a clear, usable way to work with the datasets without relying on TabArena code.

Written by the indexing model from the issue text.