extract default webpack and publish as package

[ndelangen]

We see people using our webpack config by including it, and we even document it.
@storybook/react/dist/server/config/webpack.config

But reaching deep into a package is a bad practice, because it's fragile, and makes it harder for us to refactor.

We should publish the default webpack config as it's own package.

[heinzmuller]

Just a thought, but what about having it as a named export?

import { webpackConfig } from "@storybook/react"

[ndelangen]

yeah valid point, that's an option too!

[ndelangen]

Care to make this into a PR @heinzmuller ?

[ndelangen]

We found a better solution where the default is passed as a parameter in full control mode.