Document how to use file-loader correctly for renderer webpack configs

Assets are not getting loaded after making the binary using "yarn make" on all platform (windows/Mac/Linux). We are getting error "net::ERR_FILE_NOT_FOUND". Looks like Js files are pointing to the proper location as per the package.json configuration. but assets and source files are located in different location.

And we are seeing the same issue for component source which uses Lazy import statements
```
const Login = React.lazy(() => import('./screens/login'));
```

E.g on Mac

```
Trying to load the png file from
/Contents/Resources/app/.webpack/renderer/main_window/33dbdd0177549353eeeb785d02c294af.png

But files are available in.
/Contents/Resources/app/.webpack/renderer/33dbdd0177549353eeeb785d02c294af.png

```

package.json
```
"plugins": [
[
"@electron-forge/plugin-webpack",
{
"mainConfig": "./webpack.main.config.js",
"renderer": {
"config": "./webpack.renderer.config.js",
"entryPoints": [
{
"html": "./src/index.html",
"js": "./src/app.tsx",
"name": "main_window"
}
]
}
}
]
]
```

[Sample Project https://github.com/jega-ms/electron-forge-react-typescript-webpack ](https://github.com/jega-ms/electron-forge-react-typescript-webpack
)

File Listing