Update .changeset/friendly-deers-obey.md

Co-authored-by: Rez <[email protected]>

Author: Joseph Lozano

.changeset/friendly-deers-obey.md

@@ -2,4 +2,6 @@
 '@primer/react-brand': patch
 ---
 
-Fixed overflow issues on SubdomainNavBar
+Fixed menu item overflow issues on narrow viewports in `SubdomainNavBar`. 
+
+In addition, the `body` element will now hide overflow content and prevent background scrolling when the menu is open.