Use it like so:
parser, err := kong.New(&cli, kong.Configuration(kongyaml.Loader, "/etc/myapp/config.yaml", "~/.myapp.yaml"))
YAMLFileMapper implements kong.MapperValue to decode a YAML file into a struct field.
Use it like so:
var cli struct {
Profile Profile `type:"yamlfile"`
}
func main() {
kong.Parse(&cli, kong.NamedMapper("yamlfile", kongyaml.YAMLFileMapper))
}