Reorder plotting functions in API list (#854)

Author: willschlitzer

doc/api/index.rst

@@ -25,19 +25,19 @@ Plotting data and laying out the map:
     Figure.basemap
     Figure.coast
     Figure.colorbar
-    Figure.plot
-    Figure.plot3d
     Figure.contour
     Figure.grdcontour
     Figure.grdimage
     Figure.grdview
+    Figure.image
+    Figure.inset
     Figure.legend
     Figure.logo
-    Figure.image
+    Figure.meca
+    Figure.plot
+    Figure.plot3d
     Figure.shift_origin
     Figure.text
-    Figure.meca
-    Figure.inset
 
 Color palette table generation: