Offer rollup-plugin-terser as ES6 module

[dilyanpalauzov]

I want to create an "index.html" file with rollup, which contains a script type=module and script nomodule tags. Per rollup/rollup#3536 rollup cannot call rollup/plugin-html once the ES6 and ES5 outputs are ready. So I am trying to switch to rollup API : rollup.rollup().write(). In package.json I have "type":"module" and in the file with rollup.rollup(…).write(…) I insert import {terser} from 'rollup-plugin-terser' as I had it in the rollup.config.js` file.

Node 14 says rollup-plugin-terser is expected to be in CommonJS, which does not support named exports. CommonJS modules can be imported by importing the default exports.

• Add module to package.json and allow the plugin to be loaded as ES6 module.

[TrySound]

Please check v6.1.0