feat(refacto): move everything in internal package

This allows to install katenary with `go install` and to clean up the
project folder.

internal/generator/labels/labelstructs/exchangeVolume.go

@@ -0,0 +1,20 @@
+package labelstructs
+
+import "gopkg.in/yaml.v3"
+
+type ExchangeVolume struct {
+	Name      string `yaml:"name" json:"name"`
+	MountPath string `yaml:"mountPath" json:"mountPath"`
+	Type      string `yaml:"type,omitempty" json:"type,omitempty"`
+	Init      string `yaml:"init,omitempty" json:"init,omitempty"`
+}
+
+func NewExchangeVolumes(data string) ([]*ExchangeVolume, error) {
+	mapping := []*ExchangeVolume{}
+
+	if err := yaml.Unmarshal([]byte(data), &mapping); err != nil {
+		return nil, err
+	}
+
+	return mapping, nil
+}