Updated README

README.md

@@ -30,4 +30,15 @@ in order to copy over the required css and js files.
 
 Once installation is complete your product images can be zoomed by clicking on the "Zoom In" button beneath an image.
 
+Configuration
+=========
+
+spree_product_zoom has only one configuration option, the paperclip image style to use when zooming in on an image. It defaults to `:original`.
+
+To change:
+
+```
+Spree::ProductZoom::Config.default_image_style = :image_style
+```
+
 Copyright (c) 2012 John Dyer, released under the New BSD License