Merge pull request #310 from y-yagi/fix_doc_about_generate_model

Fix doc about model generator

source/guides/models/overview.md

@@ -17,10 +17,13 @@ As first step, we generate the model:
 % bundle exec hanami generate model book
       create  lib/bookshelf/entities/book.rb
       create  lib/bookshelf/repositories/book_repository.rb
+      create  db/migrations/20170406230335_create_books.rb
       create  spec/bookshelf/entities/book_spec.rb
       create  spec/bookshelf/repositories/book_repository_spec.rb
 ```
 
+The generator gives us an entity, a repository, a migration, and accompanying test files.
+
 This is the generated entity:
 
 ```ruby
@@ -35,13 +38,6 @@ class BookRepository < Hanami::Repository
 end
 ```
 
-Then we generate the migration:
-
-```shell
-% bundle exec hanami generate migration create_books
-      create  db/migrations/20161113154510_create_books.rb
-```
-
 Let's edit the migration with the following code:
 
 ```ruby