Add `Rollup` bundler for the server

Change-Id: I38734b55ff80beeb9e0389b5a8e7c436a05477c3
diff --git a/rollup.config.js b/rollup.config.js
new file mode 100644
index 0000000..2cb8615
--- /dev/null
+++ b/rollup.config.js
@@ -0,0 +1,11 @@
+import commonjs from '@rollup/plugin-commonjs';
+import run from '@rollup/plugin-run';
+import typescript from '@rollup/plugin-typescript';
+
+const dev = process.env.NODE_ENV !== 'production';
+
+export default (async () => ({
+  input: 'app.ts',
+  output: { file: 'dist/bundle.js', sourcemap: true },
+  plugins: [typescript(), commonjs(), dev && run(), !dev && (await import('rollup-plugin-terser')).terser()],
+}))();