How to: Marshalling to String
You may need to marshal all the settings held in Viper into a string. You can
use your favorite format's marshaller with the config returned by
`AllSettings`.

```go
import (
	yaml "go.yaml.in/yaml/v3"
)

func yamlStringSettings() string {
	c := viper.AllSettings()
	bs, err := yaml.Marshal(c)
	if err != nil {
		log.Fatalf("unable to marshal config to YAML: %v", err)
	}
	return string(bs)
}
```