Apply suggestions from code review

Co-authored-by: Meghan Jones <meghanj@alum.mit.edu>

Author: willschlitzer

pygmt/src/grdclip.py

@@ -86,11 +86,17 @@ def grdclip(grid, **kwargs):
     >>> grid = pygmt.datasets.load_earth_relief(
     ...     resolution="30m", region=[10, 30, 15, 25]
     ... )  # doctest: +SKIP
+    >>> # Report the minimum and maximum data values
+    >>> [grid.data.min(), grid.data.max()]  # doctest: +SKIP
+    [179.0, 2103.0]
     >>> # Create a new grid from an input grid. Set all values below 1,000 to
     >>> # 0 and all values above 1,500 to 10,000
     >>> new_grid = pygmt.grdclip(
     ...     grid=grid, below=[1000, 0], above=[1500, 10000]
     ... )  # doctest: +SKIP
+    >>> # Report the minimum and maximum data values
+    >>> [new_grid.data.min(), new_grid.data.max()]  # doctest: +SKIP
+    [0.0, 10000.0]
     """
     with GMTTempFile(suffix=".nc") as tmpfile:
         with Session() as lib: