ENH: .gpx output in addition to geoJSON

[KCollins]

Description

Might be useful to be able to convert geoCSVs to gpx (works on Google MyMaps, where geoJSON does not).

Potential impact

Not critical; potential nice-to-have.

Potential solution(s)

Could either convert geoCSV to gpx or geoJSON to gpx.

For the latter, this might work but I'm running into bugs.

import geopandas as gpd
gdf = gpd.read_file('tmp/AMAT01RR_1min.geoJSON')
gdf.to_file('tmp/AMAT01RR_1min.gpx', 'GPX')