docs: change format to es for new transformations

Author: timhaywood

README.md

@@ -28,18 +28,20 @@ Create a `rollup.config.js` [configuration file](https://www.rollupjs.org/guide/
 
 ```js
 import afterEffectJsx from "./rollup-plugin-ae-jsx";
+import pkg from "./package.json";
 
 export default {
-  input: "src/index.js",
+  input: "src/index.ts",
   output: {
     file: "dist/index.jsx",
-    format: "cjs",
+    format: "es",
   },
-  plugins: [afterEffectsJsx()],
+  external: Object.keys(pkg.dependencies),
+  plugins: [afterEffectJsx()],
 };
 ```
 
-> - The output extension should be `.jsx` and format `cjs` to ensure After Effects compatible files.
+> - The output extension should be `.jsx` and format `es` to ensure After Effects compatible files.
 > - `rollup-plugin-ae-jsx` should be placed in `plugins` _after_ any other plugins.
 
 Then call `rollup` either via the [CLI](https://www.rollupjs.org/guide/en/#command-line-reference) or the [API](https://www.rollupjs.org/guide/en/#javascript-api).