Fix hot module reloading (react fast refresh)

[Lovor01]

I develop locally and use self-signed https. I struggled a lot until I got it working. If you have troubles, please follow my recipe:

1. create webpack.config.js in the root of project (where package.json is) and give it this content:

// change webpack default config
const defaultConfig = require( '@wordpress/scripts/config/webpack.config.js' );

if ( process.env.NODE_ENV !== 'production' ) {
	defaultConfig.devServer.server = {
		type: 'https',
		options: {
			cert: 'path to your certitificate (use forward slashes)/your-certificate.crt',
			key: 'path to ceritificate key (use forward slashes)/your-key.key'
		}
	};
	defaultConfig.devServer.allowedHosts = ['your-host-name(if changed)', 'localhost', '127.0.0.1'];

}

module.exports = defaultConfig;

2. navigate in browser to https://localhost:8887/. Browser will tell that it is unsafe... make exclusion (search in order how to do that). Reload. You must get message something like: Cannot GET /
3. Reload the page you are working on (perhaps hard reload is required).
4. Inspect console messages. It should not give errors. Only in logs you should see [HMR] Waiting for update signal from WDS...

Thats it. Test if it works!