improve read_file docstring
improve read_file docstring

geopandas/geopandas,micahcochran/geopandas,ozak/geopandas,jdmcbr/geopandas,jorisvandenbossche/geopandas,geopandas/geopandas,jdmcbr/geopandas,jorisvandenbossche/geopandas,IamJeffG/geopandas,ozak/geopandas,jorisvandenbossche/geopandas,micahcochran/geopandas,geopandas/geopandas