chore(examples): add rollup set-up

examples/rollup/rollup.config.js

@@ -0,0 +1,32 @@
+import { terser } from "rollup-plugin-terser";
+import commonjs from "@rollup/plugin-commonjs";
+import resolve from "@rollup/plugin-node-resolve";
+import serve from "rollup-plugin-serve";
+import svelte from "rollup-plugin-svelte";
+import livereload from "rollup-plugin-livereload";
+import sveltePreprocess from "svelte-preprocess";
+
+const PORT = process.env.PORT || 3000;
+const PROD = !process.env.ROLLUP_WATCH;
+
+export default {
+  input: "src/index.js",
+  output: {
+    sourcemap: !PROD,
+    format: "iife",
+    name: "app",
+    file: "public/build/bundle.js",
+  },
+  plugins: [
+    svelte({
+      dev: !PROD,
+      preprocess: sveltePreprocess(),
+      css: (css) => css.write("bundle.css", !PROD),
+    }),
+    resolve({ browser: true, dedupe: ["svelte"] }),
+    commonjs(),
+    !PROD && serve({ contentBase: ["public"], port: PORT }),
+    !PROD && livereload("public"),
+    PROD && terser(),
+  ],
+};