Update example file for GeoParquet 2.0

[paleolimbot]

Just a draft until #278 merges! This PR updates the example file to (1) write Parquet GEOMETRY as the storage type and (2) a few nits I noticed in the file.

[cholmes]

Is this ready for merge? Looks like you fixed it up, but it's still marked 'draft'.

[cholmes]

Just tried it out - thanks for doing this. It looks to be working, though geoparquet-io didn't pick up a geometry type from the Parquet metadata. If you set it let me know and I can fix my code, if you didn't set that it would be good to.

I'd say feel free to merge. I do think we should have a wider set of example data, showing projections and geography at the very least. And our test_data directory still includes arrow types, so we should get rid of those / update that script to use the stuff here. If I find time I can likely do that, but I'm slammed for the next bit.

[paleolimbot]

@cholmes Apologies for taking an inappropriately long time to circle back here, but I think this implements your suggestions (minus the extra test data).

though geoparquet-io didn't pick up a geometry type from the Parquet metadata

I added a test here to make sure it's where I think it is in the Parquet statistics...perhaps this has been cleared up in geoparquet-io by now (or the test can help fix it).

I do think we should have a wider set of example data, showing projections and geography at the very least

I'll do a release of geoarrow-data when we get around to a release of the spec...the tooling is much better now than the last time I did a release and it should be easy to get good examples of various GeoParquet versions for all the different artifacts.