Convert dataset to BIDS format

[jdpigeon]

As we gather more and more data it'll be important to have a clear specification for how it'll look.

Fortunately, the hard work in designing a structure for orgaizing neuroimaging data has already been done by the BIDS project.

I propose we refactor our current data folder to the BIDS format shown here in this template: https://github.com/INCF/BIDS-Starter-Kit/tree/master/templates

We'll also have to change the notebooks to record data in the appropriate dirs

[jdpigeon]

Just learned about the MNE-BIDS tools, which should make it even easier for us to convert the notebooks datasets to BIDS format

https://github.com/mne-tools/mne-bids