README.md in tuning-5.1.2 vs README.md in tuning-5.1.3

@@ -26,35 +26,10 @@
 $ bundle
 ```
 
 ## Usage
 
-### Controllers
-
-New callbacks before, after, around render are available:
-```ruby
-class ProductsController < ApplicationController
-
-  before_action :set_product
-  before_render :prepare_product
-
-  def edit
-  end
-
-  private
-
-  def set_product
-    @product = Product.find(params[:id])
-  end
-
-  def prepare_product
-    @product.build_picture
-  end
-
-end
-```
-
 ### Mailers
 
 Text email templates will normalize spaces and new lines like html:
 ```erb
 <% if @order.confirmed? %>
@@ -92,10 +67,10 @@
 <% end %>
 ```
 
 ### Template Handlers
 
-Ruby template handlers will automatically call to_json or to_xml:
+Ruby template handlers will automatically call to_json:
 ```ruby
 @users.map do |user|
   user.slice :name
 end
 ```