added dynamic github fields to non-ecs file

Author: terrancedejesus

detection_rules/etc/non-ecs-schema.json

@@ -150,6 +150,10 @@
     "kibana.alert.rule.type": "keyword",
     "kibana.alert.rule.threat.tactic.name": "keyword"
   },
+  "logs-github.audit-*": {
+    "github.reasons.code": "keyword",
+    "github.reasons.message": "text"
+  },
   "logs-google_workspace*": {
     "gsuite.admin": "keyword",
     "gsuite.admin.new_value": "keyword",