docs: update content

Author: mrholek

docs/content/migration/v4.md

@@ -10,6 +10,7 @@ toc: true
 
 - Upgraded from Popper v1.x to Popper v2.x.
 - Replaced Libsass with Dart Sass as our Sass compiler given Libsass was deprecated.
+
 ## Browser support
 
 - Dropped Internet Explorer 10 and 11