adding API example for loading data from Geopandas Geodataframe

[stevenlis]

Is it possible to add some examples of how to use the package if users load data from a Geopandas geodataframe? The example provided here has multiple reshape using numpy and a bit hard to follow.

And it seems to me that the coords can't take the geometry column in a geodataframe and both X and y must be numpy array instead of pandas Series. With all due respect, this is not very user-friendly, and I wonder if this could be improved in the future release.