Added a little documentation to TurboDev middleware

lib/middleware/turbo_dev.rb

@@ -1,12 +1,22 @@
 module Middleware
-  # this class cheats and bypasses rails altogether if the client attempts
-  # to download a static asset
+
+  # Cheat and bypass Rails in development mode if the client attempts to download a static asset
+  # that's already been downloaded.
+  #
+  # Also ensures that assets are not cached in development mode. Around Chrome 29, the behavior
+  # of `must-revalidate` changed and would often not request assets that had changed.
+  #
+  #  To use, include in your project and add the following to development.rb:
+  #
+  #  require 'middleware/turbo_dev'
+  #  config.middleware.insert 0, Middleware::TurboDev
+  #
   class TurboDev
     def initialize(app, settings={})
       @app = app
     end
-    def call(env)
 
+    def call(env)
       is_asset = (env['REQUEST_PATH'] =~ /^\/assets\//)
 
       # hack to bypass all middleware if serving assets, a lot faster 4.5 seconds -> 1.5 seconds
@@ -24,4 +34,5 @@ module Middleware
       [status, headers, response]
     end
   end
+
 end