feat implement the copyable interface

change.go

@@ -74,3 +74,8 @@ func (s *Settings[C]) setConfigInternal(config C, lock bool) *Settings[C] {
 func (s *Settings[C]) SetConfig(config C) *Settings[C] {
 	return s.setConfigInternal(config, true)
 }
+
+// Copy implements the xflags.Copyable interface.
+func (s *Settings[C]) Copy(config C) {
+	s.setConfigInternal(config, true)
+}

settings.go

@@ -18,6 +18,7 @@ type fileWatch struct {
 	onWatch     bool
 }
 
+// Settings is the main struct for the configuration
 type Settings[C any] struct {
 	files  fileBackend
 	stream streamBackend