Most notably update to Webpack 5. Webpack 5 supports web workers without
the need of a loader, so the `webpack-worker-loader` example has been
removed.
This removes the need to explain certain statements and imports need to
happen in a specific order. Users can now just use:
```ts
import { setDiagnosticsOptions } from 'monaco-yaml';
setDiagnosticsOptions({});
```
