Correct guide (#379)

Line 224: filename

source/guide.html.haml

@@ -221,7 +221,7 @@ introduction: >
       }
 
   :markdown
-    Notice we're using `@use 'reset';` in the `base.scss` file. When you use a
+    Notice we're using `@use 'base';` in the `styles.scss` file. When you use a
     file you don't need to include the file extension. Sass is smart and will
     figure it out for you.