css modules support?

Just an extra option passed to the API: https://lightningcss.dev/css-modules.html

Look at the plugin's main entry point to see how options are passed to the LightningCSS API. The LightningCSS documentation for CSS modules shows the required configuration. Add a new option to the plugin's configuration schema and pass it through to the LightningCSS transform. Test by building a sample Eleventy site with CSS modules enabled.

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