Fix README.markdown instructions for reloading.

Original instructions didn't seem to work on Rails 3.2.x. Followed instructions
on wiki
(https://github.com/intridea/grape/wiki/Reload-Grape-API-on-every-request-in-Rails)
and it works without issue. In the original instructions, I could only get grape
to reload my endpoint once.

Using this submitted approach looks also looks like a standard way to hook
reloading into any inbound Rails request.

CHANGELOG.markdown

@@ -6,6 +6,7 @@ Next Release
 * [#309](https://github.com/intridea/grape/pull/309): An XML format API will return an error instead of returning a string representation of the response if the latter cannot be converted to XML - [@dblock](http://github.com/dblock).
 * [#309](https://github.com/intridea/grape/pull/309): Added XML support to entities - [@johnnyiller](https://github.com/johnnyiller), [@dblock](http://github.com/dblock).
 * A formatter that raises an exception will cause the API to return a 500 error - [@dblock](http://github.com/dblock).
+* [#131](https://github.com/intridea/grape/issues/131) Fix README.markdown instructions regarding Rails 3.x reloading. Using instructions from Wiki works better - [@jyn](http://github.com/jyn)
 * Your contribution here.
 
 0.2.6 (01/11/2013)

README.markdown

@@ -1002,41 +1002,29 @@ end
 
 ### Rails 3.x
 
-Add the following to `config/environments/development.rb`:
-
-``` ruby
-@last_api_change = Time.now
-api_files = Dir["#{Rails.root}/app/api/**/*.rb"] # adjust the path to your API files
-api_reloader = ActiveSupport::FileUpdateChecker.new(api_files) do |reloader|
-  times = api_files.map { |f| File.mtime(f) }
-
-  Rails.logger.debug "! Change detected: reloading following files:"
-  api_files.each_with_index do |s,i|
-    if times[i] > @last_api_change
-      Rails.logger.debug " - #{s}"
-      load s
-    end
-  end
+Source: http://stackoverflow.com/questions/3282655/ruby-on-rails-3-reload-lib-directory-for-each-request/4368838#4368838
 
-  Rails.application.reload_routes!
-  Rails.application.routes_reloader.reload!
-  Rails.application.eager_load!
-end
+Create file `config/initializers/reload_lib.rb`
+
+```ruby
+if Rails.env.development?
+  lib_reloader = ActiveSupport::FileUpdateChecker.new(Dir["app/api/**/*"]) do
+    Rails.application.reload_routes!
+  end
 
-ActionDispatch::Reloader.to_prepare do
-  api_reloader.execute_if_updated
+  ActionDispatch::Callbacks.to_prepare do
+    lib_reloader.execute_if_updated
+  end
 end
 ```
 
-Add the following to `config/routes.rb`:
+In `config/application.rb`, add
 
-``` ruby
-require_dependency "app/api/api.rb" if Rails.env.development?
+```ruby
+config.autoload_paths += %W(#{config.root}/app/api)
+config.autoload_paths += Dir["#{config.root}/app/api/**/"]
 ```
 
-Additional `require_dependency` entries are also required for every mounted Grape endpoint.
-
-
 ## Performance Monitoring
 
 Grape integrates with NewRelic via the [newrelic-grape](https://github.com/flyerhzm/newrelic-grape) gem.