Merge pull request clap-rs#3798 from epage/docs

docs(tutorial): Update for new API

examples/tutorial_builder/README.md

@@ -372,7 +372,7 @@ NAME: "bob"
 ### Enumerated values
 
 If you have arguments of specific values you want to test for, you can use the
-`Arg::possible_values()`.
+`PossibleValuesParser` or `Arg::value_parser(["val1", ...])` for short.
 
 This allows you specify the valid values for that argument. If the user does not use one of
 those specific values, they will receive a graceful exit with error message informing them