v1.0.0-rc.* Compiled with errors: Module parse failed: Unexpected token

Bug Report

Describe the bug

When I try to run docz dev I get multiple errors regarding an appropriate loader

✖ Docz
  Compiled with some errors in 29.12s



 ERROR  Failed to compile with 3 errors              12:00:39 PM

 error  in ./node_modules/docz/dist/index.esm.js

Module parse failed: Unexpected token (15:38)
You may need an appropriate loader to handle this file type.
| import { MDXProvider } from '@mdx-js/tag';
|
> const BasePlayground = loadable(() => import('./chunk.esm2.js'));
| const Playground = props => typeof window !== 'undefined' ? (createElement(Suspense, { fallback: null },
|     createElement(BasePlayground, Object.assign({}, props)))) : null;

 @ ./.docz/app/root.jsx 9:0-59 17:2-15 20:19-23 27:25-31
 @ ./.docz/app/index.jsx
 @ multi ./node_modules/react-dev-utils/webpackHotDevClient.js ./.docz/app/index.jsx

 error  in ./node_modules/docz-theme-default/dist/index.esm.js

Module parse failed: Unexpected token (245:30)
You may need an appropriate loader to handle this file type.
| `;
|
> const CodeMirror = lazy(() => import('./chunk.esm2.js'));
| const getLanguage = (children) => {
|     const defaultLanguage = 'jsx';

 @ ./.docz/app/root.jsx 11:0-39 18:29-34
 @ ./.docz/app/index.jsx
 @ multi ./node_modules/react-dev-utils/webpackHotDevClient.js ./.docz/app/index.jsx

 error  in ./.docz/app/imports.js

Module parse failed: Unexpected token (8:11)
You may need an appropriate loader to handle this file type.
| export var imports = {
|   'src/index.mdx': function srcIndexMdx() {
>     return import(
|     /* webpackPrefetch: true, webpackChunkName: "src-index" */
|     'src/index.mdx');

 @ ./.docz/app/root.jsx 12:0-36 28:13-20
 @ ./.docz/app/index.jsx
 @ multi ./node_modules/react-dev-utils/webpackHotDevClient.js ./.docz/app/index.jsx

Environment

• node v10.15.1
• npm v6.8.0
• react v16.8.4
• npm ls webpack ├─┬ docz@1.0.0-rc.3 │ └─┬ docz-core@1.0.0-rc.3 │ └── webpack@4.29.6 └─┬ react-scripts@2.1.8 └── webpack@4.28.3

Additional context/Screenshots

[sanohin]

Also instead of installing webpack@4.28.2, you can specify it in resolutions in package.json

"resolutions": {
    "docz/**/webpack": "4.28.4"
}

[jacobjonsson]

Switching back to Storybook… such a waste of time.

No need to add those comments, the maintainer is doing a great job and does not deserve comments like that.