fix doc

docs/reference/associations.txt

@@ -130,14 +130,12 @@ macro with some additional options to tell CouchbaseOrm how to hook them up.
 
 .. code-block:: ruby
 
-   class Car
-     include CouchbaseOrm::Document
-     belongs_to :engine, class_name: "Motor", inverse_of: :machine
+   class Car < CouchabseOrm::Base
+     belongs_to :engine, class_name: "Motor"
    end
 
-   class Motor
-     include CouchbaseOrm::Document
-     has_many :machine, class_name: "Car", inverse_of: :engine
+   class Motor < CouchabseOrm::Base
+     has_many :machine, class_name: "Car"
    end
 
 Custom Foreign Keys

docs/reference/callbacks.txt

@@ -56,8 +56,7 @@ for cross-cutting concerns, like queueing up background jobs.
 
 .. code-block:: ruby
 
-   class Article
-     include CouchbaseOrm::Document
+   class Article < CouchabseOrm::Base
      attribute :name, type: String
      attribute :body, type: String
      attribute :slug, type: String
@@ -79,8 +78,7 @@ syntax as well:
 
 .. code-block:: ruby
 
-   class Article
-     include CouchbaseOrm::Document
+   class Article < CouchabseOrm::Base
      attribute :name, type: String
 
      set_callback(:create, :before) do |document|