DOC: avoid StorageOptions type alias in docstrings
Small follow-up on https://github.com/pandas-dev/pandas/pull/35655, replacing the "StorageOptions" with a plain "dict" in the docstrings ("StorageOptions" is not something known to users, in the type annotations it will expand but not in the docstrings)

(cc @martindurant)
I thought I was following style :| > I thought I was following style :|

In any case, it the first PR adding storage_options, it was not done like that ;) lgtm