Fix assign_attributes documentation

lib/aws-record/record/item_operations.rb

@@ -82,8 +82,7 @@ def save(opts = {})
       end
 
 
-      # Deletes the item instance that matches the key values of this item
-      # instance in Amazon DynamoDB.
+      # Assigns the attributes provided onto the model.
       #
       # @example Usage Example
       #   class MyModel