(enh) add example to rollup build against CDN/esm modules

test/builds/rollup_import_cdn_build_esm.mjs

@@ -0,0 +1,16 @@
+// rollup.config.js
+import commonjs from "@rollup/plugin-commonjs";
+
+export default {
+  input: "test/builds/cdn_build_as_esm.mjs",
+  output: {
+    file: "build/bundle.js",
+    format: "iife",
+  },
+  plugins: [
+    commonjs({
+      include: "build/**", // Default: undefined
+      exclude: ["node_modules/**"], // Default: undefined
+    }),
+  ],
+};