New,Update now support anchors and aliases

cmd/constant.go

@@ -10,6 +10,8 @@ var printMode = "v"
 var printLength = false
 var unwrapScalar = true
 var customStyle = ""
+var anchorName = ""
+var makeAlias = false
 var stripComments = false
 var collectIntoArray = false
 var writeInplace = false