Add Renovate configuration for npm updates

Author: NullVoxPopuli

.github/renovate.json5

@@ -0,0 +1,7 @@
+// Docs:
+// https://docs.renovatebot.com/configuration-options/
+{
+  "extends": [
+    "github>NullVoxPopuli/renovate:npm.json5"
+  ]
+}