DOC: Add missing gallery order for Plot types > Gridded data

Forgot to add this file in matplotlib#31714.

This maintains the order that has been there before.

Author: timhoffm

galleries/plot_types/arrays/gallery_order.txt

@@ -0,0 +1,8 @@
+# Explicit example order. See https://matplotlib.org/devdocs/devel/document.html#order-examples
+imshow
+pcolormesh
+contour
+contourf
+barbs
+quiver
+streamplot