README.md in gdatastore_mapper-0.1.2 vs README.md in gdatastore_mapper-0.1.3

@@ -1,15 +1,40 @@
 # GdatastoreMapper
 
 GdatastoreMapper is a mapper framework for Google Cloud Datastore in Ruby / Ruby on Rails.
 Once you install GdatastoreMapper you can use Google Cloud Datastore like ActiveRecord.
 
+## Table of Contents
+- [Requirements](#requirements)
+- [Installation](#installation)
+- [Configuration](#configuration)
+- [Model Setting](#model-setting)
+- [Persistence Methods](#persistence-methods)
+- [Scoping Methods](#scoping-methods)
+- [Timestamp](#timestamp)
+- [Associations](#associations)
+  - [One to Many](#one-to-many)
+- [Development](#development)
+
+## Requirements
+
+GdatastoreMapper requires Rails version >= 4.2 (of course it's working for Rails 5)
+
+google-cloud >= 0.27
+
+
 ## Installation
 
+Execute rails new with --skip-active-record
+```
+$ rails new your_project --skip-active-record
+```
+
 Add this line to your application's Gemfile:
 
 ```ruby
+gem 'google-cloud'
 gem 'gdatastore_mapper'
 ```
 
 And then execute:
 
@@ -38,18 +63,18 @@
 test:
   dataset_id: your-google-cloud-platform-project-id
   emulator_host: localhost:8444
 ```
 
-## Usage
+## Model Setting
 
 Only 2 things you need to do.
 
 1. To include GdatastoreMapper
 2. To set attr_accessor as column
 
-That's it!
+That's it! No need to db:migrate.
 
 ```ruby
 class Book
   include GdatastoreMapper::Base
 
@@ -119,9 +144,11 @@
 ## Timestamp
 
 All records have created_at and updated_at. They will be updated automatically.
 
 ## Associations
+
+### One to Many
 
 example of one to many relationship
 
 ```ruby
 class Book