Verify Webpack Documentation

The documentation for Webpack didn't work for me

https://github.com/43081j/postcss-lit/blob/48c6f363faad026f151065fb61569f4db1fde688/README.md?plain=1#L33-L60

When I switched it around it started working as expected. Here's our order:

```
{
test: /\.ts$/,
use: [
'babel-loader',
'ts-loader',
'postcss-loader',
],
exclude: /node_modules/
}
```

We're on Webpack version 5 in a monorepo, though I don't think that matters much.

After further investigation, as your readme states "_postcss will transform your CSS before typescript transpiles_", Webpack loaders are executed in reverse order (see [Webpack's documentation](https://webpack.js.org/concepts/loaders/#configuration)). So we'd want `postcss-loader` last in the array so it can be first. I still don't understand why Webpack works this way, I'm sure there's a lengthy thread somewhere but it's illogical to me.