- compile default pages correctly into `.next`
- add missing runtime dependencies

* Set a default path for wasm modules

* Added the mimetype "application/wasm" for wasm files

* Upgrade write-file-webpack-plugin to 4.4.1

* Made dynamic(import()) in test to dynamic(() => import())

fixes #5355 

As prepare is only needed to boot up the hot reloader + exportPathMap routes in development, it's not longer a requirement in the production server.

* Add analyze-bundles example

* housekeeping: with-webpack-bundle-analyzer example

* analyze-bundles example: revert the version of faker library

* analyze-bundles add analyze:server and analyze:browser to scripts

* with-webpack-bundle-analyzer example: fix typo

- Implements Lerna
- Moves all source code into `packages/next`
- Keeps integration tests in the root directory

- `<details>` and `<ul>` cannot be inside `<p>` and it will not be parsed correctly by the MDX tokenizer.
- `sh` is not a valid language name for syntax highlighting libs (e.g. [highlight.js](https://github.com/highlightjs/highlight.js/tree/master/src/languages)).

We don't need to `React.cloneElement`, twice.

This PR removes the obsolete `_containerProps` context.