[Python][Doc] Documentation for Test Groups out of sync #33267

In the Python documentation for Test Groups it's stated:

We have many tests that are grouped together using pytest marks. Some of these are disabled by default. To enable a test group, pass --$GROUP_NAME, e.g. --parquet. [continues]
However, I get:

$ pytest --parquet # from arrow/python dir
ERROR: usage: pytest [options] [file_or_dir] [file_or_dir] [...]
pytest: error: unrecognized arguments: --parquet

Am I interpreting the docs wrong or has something changed since writing the docs?

Related: pytest --markers only reports the full list of pytest Marks when I'm in the arrow/python/pyarrow directory but not arrow/python. When I'm in the arrow/python/pyarrow subdirectory, marks work as expected (ie pytest -m parquet works).

Reporter: Bryce Mecum / @amoeba

_{Note: This issue was originally created as ARROW-18066. Please see the migration documentation for further details.}