Remove factorization

I think this sentence is easier to understand that way.

Author: greg0ire

contributing/code/standards.rst

@@ -96,7 +96,7 @@ Naming Conventions
 * Use camelCase, not underscores, for variable, function and method
   names, arguments;
 
-* Use underscores for option, parameter names;
+* Use underscores for option names and parameter names;
 
 * Use namespaces for all classes;