[ENH] Add OpenNeuro Dataset Compatibility to Examples/Tutorials

As of now, mne sample data is hosted in OSF through owner privileges. My understanding is that the CIs have to pull and download the sample data every time (if that’s wrong then this would probably slow things down) so it might make sense to have a clean API to make OpenNeuro data accessible maybe with nice keywords like JH_ECoG.

cc @larsoner, @adam2392

[hoechenberger]

https://github.com/hoechenberger/openneuro-py

[alexrockhill]

I think openneuro-py has pretty much everything already needed to include sample data using it. The only things that would be nice to add are documentation and regular expressions instead of just startswith for including files. For the latter, the main use would be including specific runs and I guess you sometimes wouldn’t need the sidecar files but they are so small it seems good to include them. Otherwise, this issue might be closed and it’s just a matter of adding an example or two to the docs so that this becomes a way to use example data regularly. Those seem like better issues on the openneuro-py repo.