[Docs] Clarify Saved Data Location on Mac about eeg-expy

[retiutut]

I like the language already in place for the windows file location:

The default directory is found at the location C:\Users*USER_NAME*.eegnb an example of which is pictured below.

[retiutut]

On Mac, the default directory is found at the location /Users/*USER_NAME*/.eegnb/, as seen in the picture below.
[Use Picture Attached to this Issue]

[retiutut]

John suggests maybe just copying this data to the Documents folder.

It's still important for data to be stored in these hidden folders, as this is a standard used by applications.

[JohnGriffiths]

@retiutut - do you need any help / pointers / discussion in implementing this?

[retiutut]

I think there is enough info here to implement a solution. It might help for me to ask some questions later.

Maybe this involves:

• Make a change to the Docs to clarify info
• Making a change to the code in the eeg-nb command line script