The biome analysis example fails in 19w36a+ worlds, including 1.15

[dhouck]

The biome format changed in 19w36a, and the included biome analysis script completely fails for those worlds. The chunk files no longer store the full biome information (they store data for each 4×4×4 region, and some interpolation is done to turn that into the full information), and I don’t think the details of the interpolation is known, but we could get at least a rough sample. Additionally, the script assumes the Biome array is present, which it isn’t always, so it crashes for partially-generated chunks.