Update README.markdown

The description of the process to decide whether you can update an employer referred to their organisation, while the example refers to their employer. Changed to reference to organisation to employer to make the example clearer.

README.markdown

@@ -405,7 +405,7 @@ class LlamasController < ApplicationController
 end
 ```
 
-If you want to authorize all actions the same way, use the special `all_actions` hash key. For instance, if you have nested resources, you might say "you're allowed to do anything you like with an employee if you're allowed to update their organization".
+If you want to authorize all actions the same way, use the special `all_actions` hash key. For instance, if you have nested resources, you might say "you're allowed to do anything you like with an employee if you're allowed to update their employer".
 
 ```ruby
 class EmployeesController < ApplicationController