Add grdtrack and load_ocean_ridge_points tutorial data to docs

PyGMT grdtrack added under "Operations on grids" (though it does require a tabular data input). Also added the ocean_ridge_points tutorial dataset used in grdtrack's unit tests and reordered the tutorial datasets alphabetically.

Author: weiji14

doc/api/index.rst

@@ -59,6 +59,7 @@ Operations on grids:
     :toctree: generated
 
     grdinfo
+    grdtrack
 
 
 Miscellaneous
@@ -87,10 +88,10 @@ and store them in the GMT cache folder.
     :toctree: generated
 
     datasets.load_earth_relief
-    datasets.load_usgs_quakes
-    datasets.load_sample_bathymetry
     datasets.load_japan_quakes
-
+    datasets.load_ocean_ridge_points
+    datasets.load_sample_bathymetry
+    datasets.load_usgs_quakes
 
 .. automodule:: pygmt.exceptions
 

pygmt/sampling.py

@@ -29,6 +29,8 @@ def grdtrack(
     bilinear, B-spline or nearest-neighbor (see -n) interpolation is used, requiring
     boundary conditions at the limits of the region.
 
+    Full option list at :gmt-docs:`grdtrack.html`
+
     Parameters
     ----------
     points: pandas.DataFrame