chore: add renovate.json to group dependency pr's (#437)

Author: tommyd450

renovate.json

@@ -0,0 +1,6 @@
+{
+    "$schema": "https://docs.renovatebot.com/renovate-schema.json",
+    "extends": [
+        "github>securesign/actions:centralRenovate.json"
+    ]
+}