Release v1.0.21

1. add api template support in goctl, use "goctl api go template" to generate the default templates, remove any file and regenerate it with default if you want to discard the changes
2. add logx.Alert(msg) to log the alert into the error.log, monitor it and make the alerts
3. add fx.Split(n) to split as chunks by given size n
4. minor improvements