Docs: fix New York longitude sign in partial overwrite example

[fallintoplace]

Problem

The partial overwrite example in mkdocs/docs/api.md uses New York with a positive longitude:

{"city": "New York", "lat": 40.7128, "long": 74.0060}

and the rendered output also shows 74.006.

For New York City, the longitude should be negative (-74.0060).

Proposed fix

Update both the example input row and the shown tbl.scan().to_arrow() output to use the correct negative longitude so the example remains internally consistent.