Missing datafiles in Ch 4 and 7

[justb4]

After #78. Got the following error in the GeoPandas section in Ch 4.

Think the idea is to first download https://www.naturalearthdata.com/http//www.naturalearthdata.com/download/10m/cultural/ne_10m_admin_0_countries.zip and unzip in data folder? Maybe it is better to have a small subset checked in? Or else provide some instruction. Or maybe use a small subset or the existing countries.gpkg? This data file is also used in Ch 7.

Also

• pd.read_csv('../data/stadium.csv') `
• gpd.read_file('../data/world.geojson')

Are missing.

[justb4]

stadium.csv is under jupyter/content/notebooks/ so we can simply move.