Update css/properties/transition.json

Author: caugner

css/properties/transition.json

@@ -420,6 +420,7 @@
         },
         "normal": {
           "__compat": {
+            "spec_url": "https://drafts.csswg.org/css-transitions-2/#typedef-transition-behavior-value:~:text=normal,-%7C%20allow",
             "spec_url": "https://drafts.csswg.org/css-transitions-2/#typedef-transition-behavior-value:~:text=normal,-%7C%20allow",
             "support": {
               "chrome": {