Update README.md

Add a mention for https://github.com/radar/paranoia/issues/109#issuecomment-74455252

README.md

@@ -124,6 +124,16 @@ def product
 end
 ```
 
+If you want to include associated soft-deleted objects, you can (un)scope the accociation:
+
+``` ruby
+class Person < ActiveRecord::Base
+  belongs_to :group, -> { with_deleted }
+end
+
+Person.includes(:group).all
+```
+
 If you want to find all records, even those which are deleted:
 
 ``` ruby