chore: enable renovate for vulnerability alerts and lock file maintenance (#128)

Author: trivikr

.github/renovate.json

@@ -0,0 +1,11 @@
+{
+  "$schema": "https://docs.renovatebot.com/renovate-schema.json",
+  "extends": ["config:base", ":dependencyDashboard"],
+  "vulnerabilityAlerts": {
+    "enabled": true
+  },
+  "lockFileMaintenance": {
+    "enabled": true,
+    "schedule": ["before 3am on the first day of the month"]
+  }
+}