chore: migrate rollup config

Author: nikku

package.json

@@ -50,7 +50,7 @@
     "lint": "eslint . --ext js,ts",
     "vscode:prepublish": "npm run compile",
     "compile": "run-s compile:clean compile:app compile:tests",
-    "compile:app": "rollup -c rollup.config.js --bundleConfigAsCjs",
+    "compile:app": "rollup -c rollup.config.mjs",
     "compile:tests": "tsc -p ./src/test",
     "compile:clean": "shx rm -rf out",
     "watch:app": "npm run compile:app -- -w",

rollup.config.js renamed to rollup.config.mjs

@@ -1,13 +1,11 @@
-/* eslint-env node */
-
 import resolve from '@rollup/plugin-node-resolve';
 import commonjs from '@rollup/plugin-commonjs';
 import url from '@rollup/plugin-url';
 import typescript from '@rollup/plugin-typescript';
 
 import css from 'rollup-plugin-css-only';
 
-module.exports = [
+export default [
 
   // client
   {