README examples raise errors as written

[tomalrussell]

Hi @wang-boyu - thanks for submitting this package to JOSS, it looks good. I'm going to raise a few issues but all should be fixable.

The code snippets in the README (and docs front page) refer to 'path/to/your/geospatial_data.shp' without specifying what that should contain.

1. I'd suggest using a GeoDataFrame literal here, or a small example dataset e.g. from geodatasets as geopandas uses for some tutorials.
2. Note any restrictions on geometry types - as I understand it, the methods accept either all Point or all Polygon

pysgn/README.md

Line 29 in 6945f88

gdf = gpd.read_file('path/to/your/geospatial_data.shp')

import geodatasets
# ...
gdf = gpd.read_file(geodatasets.get_path("geoda groceries")).explode()  # explode to go from Multi- to Points

Part of openjournals/joss-reviews#9346

[wang-boyu]

Updated readme file to use geodatasets in the code examples now, as part of #24. The updated readme now looks like this: https://github.com/wang-boyu/pysgn/blob/docs/use-geodatasets/README.md