Add destination link metadata

internal/config/config.go

@@ -33,6 +33,7 @@ type Destination struct {
 	Publish   *PublishPolicy `yaml:"publish"`
 	Transform Transform      `yaml:"transform"`
 	PathMap   PathMapping    `yaml:"path_mapping"`
+	Links     *Links         `yaml:"links"`
 	Transfer  TransferPolicy `yaml:"transfer"`
 }
 
@@ -85,6 +86,11 @@ type PathMapping struct {
 	Mode string `yaml:"mode"`
 }
 
+type Links struct {
+	BaseURL string `yaml:"base_url"`
+	Primary string `yaml:"primary"`
+}
+
 type TransferPolicy struct {
 	OnDestinationSame  string `yaml:"on_destination_same"`
 	OnDestinationOlder string `yaml:"on_destination_older"`