Initial documentation and functionality

[palday]

Almost everything is delegated to MNE-Python directly, with the exception of create_info, which also serves as an example for how to write override methods.

[ararslan]

Worth including our set_montage! function? It's handy but doesn't really mimic the MNE interface like the rest of the stuff, so perhaps not in scope for this package.

[palday]

For now, I would leave set_montage! out because it doesn't follow the MNE interface (like you said). I guess it's something we see how users fare -- if we get issues about Montage related functionality failing via the standard PyCall wrapping, then we can add that in. But that is a good point to add to the README -- those types of failures can be raised as issues and potentially added in in future releases.