raster.sample("usgs3dep-1meter-dem") requires passing "catalog" kwarg

[scottyhq]

I was surprised that this returns an empty dataframe and doesn't appear to have any logging information even with sliderule.init(verbose=True)

gdf = raster.sample("usgs3dep-1meter-dem", [[-108.0,39.0]])

The API docs don't mention this:
https://slideruleearth.io/web/rtd/api_reference/raster.html#sliderule.raster.sample

I guess 3dep is also a 'special case' like HLS:
https://slideruleearth.io/web/rtd/user_guide/GeoRaster.html#special-case-hls

I figured out to pass the catalog by looking at the tests:

sliderule/clients/python/tests/test_3dep.py

Lines 16 to 18 in 20a5b41

	def test_sample(self, init):
	geojson = earthdata.tnm(short_name='Digital Elevation Model (DEM) 1 meter', polygon=region)
	gdf = raster.sample("usgs3dep-1meter-dem", [[-108.0,39.0]], {"catalog": geojson})

link to this issue on other ideas for raster docs improvements #372

[scottyhq]

Tacking on another note to document "single_stop": True
(added in #422)