chore: provide usage instruction for CLI argument failures (#12309)

* chore: add usage to # cli arg failures

cli/errors.go

@@ -45,7 +45,8 @@ func (RootCmd) errorExample() *clibase.Cmd {
 	apiError.(*codersdk.Error).Helper = "Have you tried turning it off and on again?"
 
 	//nolint:errorlint,forcetypeassert
-	apiErrorNoHelper := apiError.(*codersdk.Error)
+	cpy := *apiError.(*codersdk.Error)
+	apiErrorNoHelper := &cpy
 	apiErrorNoHelper.Helper = ""
 
 	// Some flags
@@ -94,7 +95,6 @@ func (RootCmd) errorExample() *clibase.Cmd {
 					)
 				},
 			},
-
 			{
 				Use: "validation",
 				Options: clibase.OptionSet{
@@ -114,6 +114,16 @@ func (RootCmd) errorExample() *clibase.Cmd {
 					return nil
 				},
 			},
+			{
+				Use: "arg-required <required>",
+				Middleware: clibase.Chain(
+					clibase.RequireNArgs(1),
+				),
+				Handler: func(i *clibase.Invocation) error {
+					_, _ = fmt.Fprint(i.Stdout, "Try running this without an argument\n")
+					return nil
+				},
+			},
 		},
 	}