add support to actually specify prompt

raymenu/vendor/github.com/alexflint/go-arg/register.go

@@ -0,0 +1,21 @@
+package arg
+
+var registrations []interface{}
+
+// Register adds a struct that will be added to the command line arguments parsed
+// by any call to arg.Parse or arg.MustParse
+//
+// This allows you to have command line arguments defined per-package
+//
+//	package foo
+//
+//	var args struct {
+//		CacheSize int `arg:"--foo-cache-size"`
+//	}
+//
+//	func init() {
+//		arg.Register(&args)
+//	}
+func Register(dest any) {
+	registrations = append(registrations, dest)
+}