Gallery examples: Fix typos (#3341)

Author: yvonnefroehlich

examples/gallery/maps/country_polygons.py

@@ -22,7 +22,7 @@
     water="white",
     frame="afg",
     dcw=[
-        # Great Britain (country code) with seagrean land
+        # Great Britain (country code) with seagreen land
         "GB+gseagreen",
         # Italy with a red border
         "IT+p0.5p,red3",

examples/gallery/symbols/points.py

@@ -2,8 +2,8 @@
 Points
 ======
 
-The :meth:`pygmt.Figure.plot` method can plot points. The plot symbol and size
-is set with the ``style`` parameter.
+The :meth:`pygmt.Figure.plot` method can plot data points. The symbol and
+size are set with the ``style`` parameter.
 """
 
 # %%