accept CSS string in registerPreviewStyle

website/site/content/docs/beta-features.md

@@ -46,3 +46,18 @@ init({
 // The registry works as expected, and can be used before or after init.
 registry.registerPreviewTemplate(...);
 ```
+
+## Raw CSS in `registerPreviewStyle`
+`registerPreviewStyle` can now accept a CSS string, in addition to accepting a url. The feature is activated by passing in an object as the second argument, with `raw` set to a truthy value.This is critical for integrating with modern build tooling. Here's an example using webpack:
+
+```js
+/**
+ * Assumes a webpack project with `sass-loader` and `css-loader` installed.
+ * Takes advantage of the `toString` method in the return value of `css-loader`.
+ */
+import CMS from 'netlify-cms';
+import styles from '!css-loader!sass-loader!../main.scss'
+
+CMS.registerPreviewStyle(styles.toString(), { raw: true })
+```
+