CLN/DOC: DataFrame.to_parquet supports file-like objects
Adds documentation and type-hints for supporting file-like objects when `engine == 'pyarrow'`; relevant to #30081. Tests for this behavior currently exist in `io.test_parquet.py`:

````
@td.skip_if_no("pyarrow")
    def test_read_file_like_obj_support(self, df_compat):
        buffer = BytesIO()
        df_compat.to_parquet(buffer)
        df_from_buf = pd.read_parquet(buffer)
        tm.assert_frame_equal(df_compat, df_from_buf)
````

Perhaps the restrictions on the arguments when path is not a string:

* partition_cols must be None; and
* engine must end up being pyarrow

should be checked directly in `DataFrame.to_parquet`, but I'm leaving this out as that is an API change that could be made in a subsequent PR. The latter gives the clear error message `TypeError: expected str, bytes or os.PathLike object, not _io.BytesIO` but the former raises `AttributeError: 'NoneType' object has no attribute '_isfilestore'` which is slightly confusing.

Another API change that could be made subsequently is changing the `path` argument to `path_or_buf`, consistent with `DataFrame.to_csv`.
would take a separate PR for path -> path_or_buf (needs deprecation) Thanks @rhshadrach.