Update README

Remove mentions of `experimentalCodeSplitting` since we now support Rollup >= 1.

Author: kristoferbaxter

README.md

@@ -50,27 +50,6 @@ export default {
 }
 ```
 
-### Code Splitting via Dynamic Imports
-
-This plugin supports code splitting with Rollup's `experimentalCodeSplitting` feature. Enable code splitting in your Rollup configuration and each output bundle will be minified by Closure Compiler.
-
-```js
-// rollup.config.js
-import compiler from '@ampproject/rollup-plugin-closure-compiler';
-
-export default {
-  input: 'main.js',
-  output: {
-    dir: 'public/module',
-    format: 'es',
-  },
-  experimentalCodeSplitting: true,
-  plugins: [
-    compiler(),
-  ],
-}
-```
-
 ### Automatic Closure Configuration
 
 This plugin will modify the enable the `assume_function_wrapper` output option for Closure Compiler when `es` format is specifed to Rollup. **Note**: This is overrideable via passed flags and options.
@@ -120,4 +99,4 @@ The AMP Project strives for a positive and growing project community that provid
 
 ## License
 
-rollup-plugin-closure-compiler is licensed under the [Apache License, Version 2.0](LICENSE).
+rollup-plugin-closure-compiler is licensed under the [Apache License, Version 2.0](LICENSE).