Update parameters.rst

Author: afurculita

service_container/parameters.rst

@@ -242,9 +242,7 @@ See :doc:`/configuration/external_parameters`.
 Constants as Parameters
 -----------------------
 
-Setting PHP constants as parameters is also supported.
-To take advantage of this feature, map the name of your constant to a parameter
-key and define the type as ``constant``.
+Setting PHP constants as parameters is also supported:
 
 .. configuration-block::