updated rule and check json to add a11y tags

Author: chikara1608

lib/checks/forms/autocomplete-valid.json

@@ -2,7 +2,7 @@
   "id": "autocomplete-valid",
   "evaluate": "autocomplete-a11y-evaluate",
   "metadata": {
-    "impact": "serious",
+    "impact": "moderate",
     "messages": {
       "pass": "the autocomplete attribute is correctly formatted",
       "fail": "Add autocomplete attribute to form fields with a valid value as per HTML specification. In \"name\" attribute of field, prefer to use standard autocomplete value since browsers use \"name\" to suggest autofill. For field with no standard autocomplete value (eg: College ID), prefer to use autocomplete=\"on\"."

lib/rules/autocomplete-valid.json

@@ -8,7 +8,9 @@
     "wcag135",
     "EN-301-549",
     "EN-9.1.3.5",
-    "ACT"
+    "ACT",
+    "a11y-engine", 
+    "a11y-engine-experimental"
   ],
   "actIds": ["73f2c2"],
   "metadata": {