Update Defaults documentation

doc/01-sensible-defaults.md

@@ -23,8 +23,28 @@ Your modules and classes would, of course, follow the same structure: `API::V1::
 `API::V1::Post::Operation::Create` and so on and so forth.
 
 If you adhere to this structure, the gem will be able to locate all of your classes without explicit
-configuration (i.e. no `#policy` or `#contract` calls etc.).
+configuration (i.e. no `#policy` or `#contract` calls etc.). This will save you a lot of time and is
+highly recommended, especially when used in conjunction with the provided CRUD operations.
 
-This will save you a lot of time and is highly recommended, especially when used in conjunction with
-the provided CRUD operations. If no policy or contract are specified, then the provided operations
-will simply skip the authorization/validation step.
+To leverage automatic discovery, include `Pragma::Operation::Defaults` in your operation:
+
+```ruby
+module API
+  module V1
+    module Post
+      module Operation
+        class Create < Pragma::Operation::Base
+          include Pragma::Operation::Defaults
+
+          def call
+            # You can use `decorate`, `validate` and `authorize` without having to explicitly
+            # specify the decorator, validator and policy classes.
+            #
+            # ...
+          end
+        end
+      end
+    end
+  end
+end
+```