[asset pipeline] Add production assets section

railties/guides/source/asset_pipeline.textile

@@ -95,7 +95,18 @@ In addition to this single layer of pre-processing, we can also put on additiona
 
 Keep in mind that the order of these pre-processors is important. For example, if we called our JavaScript file +app/assets/javascripts/projects.js.erb.coffee+ then it would be processed with the CoffeeScript interpreter first, which wouldn't understand ERB and therefore we would run into problems.
 
-h3. Compressing Assets
+h3. Production Assets
+
+In the production environment, assets are served slightly differently to how they are served in the development environment.
+
+TODO: Talk here about:
+ * Rack::Cache's caching
+ * Sprocket's auto-generated MD5 hashes
+ * Sass-rails's handy +image_url+ helpers
+ * ERB pre-processing and +asset_url+
+
+
+h4. Compressing Assets
 
 The default Gemfile also includes the "uglifier":https://github.com/lautis/uglifier gem. This gem wraps "UglifierJS":https://github.com/mishoo/UglifyJS (written for NodeJS) in Ruby. It compress your code by removing white spaces and other magical things like changing your if and else statements to ternary operators when possible.