docs: improve documentation

Author: sokra

README.md

@@ -265,6 +265,8 @@ This improves performance and memory usage a lot, but isn't as stable as the nor
 
 When combined with `experiments.layers`, this adds a `layer` option to the loader options to specify the layer of the css execution.
 
+You need to have at least webpack 5.33.2.
+
 ### Loader Options
 
 |              Name               |         Type         |              Default               | Description                                                                       |

src/loader.js

@@ -191,7 +191,7 @@ export function pitch(request) {
     if (!this.importModule) {
       callback(
         new Error(
-          "You are using experimentalUseImportModule but 'this.importModule' is not available in loader context. You need to have at least webpack 5.32.0."
+          "You are using experimentalUseImportModule but 'this.importModule' is not available in loader context. You need to have at least webpack 5.33.2."
         )
       );
       return;