Default to type: module (#447)

babel.config.cjs

@@ -0,0 +1,16 @@
+// Copyright 2017-2021 @polkadot/ui authors & contributors
+// SPDX-License-Identifier: Apache-2.0
+
+const base = require('@polkadot/dev/config/babel-config-cjs.cjs');
+
+module.exports = Object.keys(base).reduce((config, key) => {
+  config[key] = base[key];
+
+  if (key === 'plugins') {
+    config[key] = config[key].concat([
+      'transform-vue-template'
+    ]);
+  }
+
+  return config;
+}, {});