DOC: pyarrow.rst: Add missing IO readers
# Changes

* Add `read_parquet` and `read_table` (experimental) to the list of IO readers that support the PyArrow engine.
* Alphabetize list to improve readability.


- [x] (N/A) closes #xxxx
- [x] (N/A) [Tests added and passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#writing-tests) if fixing a bug or adding a new feature
- [x] (N/A) All [code checks passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit).
- [x] (N/A) Added [type annotations](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#type-hints) to new arguments/methods/functions.
- [x] (N/A) Added an entry in the latest `doc/source/whatsnew/vX.X.X.rst` file if fixing a bug or adding a new feature.

Thanks @mattayes  Thanks for the quick review/merge @mroeschke!