Use 'Note' rather than 'Notes' as docstring section header (#1813)

Author: Meghan Jones

pygmt/datasets/earth_age.py

@@ -54,8 +54,8 @@ def load_earth_age(resolution="01d", region=None, registration=None):
         The Earth seafloor crustal age grid. Coordinates are latitude and
         longitude in degrees. Age is in millions of years (Myr).
 
-    Notes
-    -----
+    Note
+    ----
     The :class:`xarray.DataArray` grid doesn't support slice operation, for
     Earth seafloor crustal age with resolutions of 5 arc-minutes or higher,
     which are stored as smaller tiles.

pygmt/datasets/earth_relief.py

@@ -62,8 +62,8 @@ def load_earth_relief(resolution="01d", region=None, registration=None, use_srtm
         The Earth relief grid. Coordinates are latitude and longitude in
         degrees. Relief is in meters.
 
-    Notes
-    -----
+    Note
+    ----
     The :class:`xarray.DataArray` grid doesn't support slice operation, for
     Earth relief data with resolutions of 5 arc-minutes or higher, which are
     stored as smaller tiles.

pygmt/src/grdhisteq.py

@@ -202,8 +202,8 @@ def equalize_grid(
         -------
         :meth:`pygmt.grd2cpt`
 
-        Notes
-        -----
+        Note
+        ----
         This method does a weighted histogram equalization for geographic
         grids to account for node area varying with latitude.
         """
@@ -312,8 +312,8 @@ def compute_bins(
         -------
         :meth:`pygmt.grd2cpt`
 
-        Notes
-        -----
+        Note
+        ----
         This method does a weighted histogram equalization for geographic
         grids to account for node area varying with latitude.
         """