chore: upgrade linting, apply linting

eslint.config.mjs

@@ -0,0 +1,13 @@
+import ivuorinenConfig from '@ivuorinen/eslint-config';
+
+export default [
+  ...ivuorinenConfig,
+
+  // your modifications
+  {
+    rules: {
+      // "no-unused-vars": "warn"
+      "n/no-unpublished-import": "off"
+    }
+  }
+];