Add inline example to load_earth_geoid (#2258)

Co-authored-by: Yvonne Fröhlich <[email protected]>

pygmt/datasets/earth_geoid.py

@@ -7,6 +7,8 @@
 from pygmt.datasets.load_remote_dataset import _load_remote_dataset
 from pygmt.helpers import kwargs_to_strings
 
+__doctest_skip__ = ["load_earth_geoid"]
+
 
 @kwargs_to_strings(region="sequence")
 def load_earth_geoid(resolution="01d", region=None, registration=None):
@@ -57,6 +59,21 @@ def load_earth_geoid(resolution="01d", region=None, registration=None):
  The :class:`xarray.DataArray` grid doesn't support slice operation, for
  Earth geoid grids with resolutions of 5 arc-minutes or higher,
  which are stored as smaller tiles.
+
+ Examples
+ --------
+
+ >>> from pygmt.datasets import load_earth_geoid
+ >>> # load the default grid (gridline-registered 1 arc-degree grid)
+ >>> grid = load_earth_geoid()
+ >>> # load the 30 arc-minutes grid with "gridline" registration
+ >>> grid = load_earth_geoid(resolution="30m", registration="gridline")
+ >>> # load high-resolution (5 arc-minutes) grid for a specific region
+ >>> grid = load_earth_geoid(
+ ... resolution="05m",
+ ... region=[120, 160, 30, 60],
+ ... registration="gridline",
+ ... )
  """
  grid = _load_remote_dataset(
  dataset_name="earth_geoid",