added missing docs

doc/providers/validator.rst

@@ -8,7 +8,8 @@ standalone.
 Parameters
 ----------
 
-none
+* **validator.validator_service_ids**: An array of service names representing
+  validators.
 
 Services
 --------
@@ -24,10 +25,6 @@ Services
   data class, which takes a ClassMetadata argument. Then you can set
   constraints on this ClassMetadata instance.
 
-* **validator.validator_factory**: Factory for ConstraintValidators. Defaults
-  to a standard ``ConstraintValidatorFactory``. Mostly used internally by the
-  Validator.
-
 Registering
 -----------