- Add command to install `air` for hot reloading in `Makefile`
- Add `dev` command to run the application with hot reload in `Makefile`
- Add `vendor` command to tidy and verify module dependencies in `Makefile`
- Update log synchronization method to use `log.Default().Sync()` in `cmd/cmd.go`
- Change variadic parameter type from `interface{}` to `any` in logging functions
- Remove `Sync` function from `pkg/log/log.go`
ref: https://github.com/uber-go/zap/issues/880
Signed-off-by: appleboy <appleboy.tw@gmail.com>