add Aaron's tweet example to docs

[raybellwaves]

I added a minor tweak here to use cfVarName which matches the name of the returned DataArray.

url = "simplecache::https://www.ncei.noaa.gov/thredds/catalog/model-gefs-003/202008/20200831/catalog.xml"
intake.open_thredds_merged(
    url,
    path=["NCEP gens-a Grid 3 Member-Forecast *-372 for 2020-08-31 00:00*"],
    driver="netcdf",
    concat_kwargs={"dim": "member"},
    xarray_kwargs=dict(
        engine="cfgrib",
        backend_kwargs=dict(
            filter_by_keys={"typeOfLevel": "heightAboveGround", "cfVarName": "t2m"}
        ),
    ),
).to_dask()

[aaronspring]

please go ahead and open a PR adding this example. then afterwards we can release IMO

[aaronspring]

even better to use concat_kwargs={"dim": "number"}, # because thats the coord name already