fix(menu): Edit a11y docs (#4655)

Author: Dottenpixel

ui/components/menus/docs.mdx

@@ -36,7 +36,7 @@ The target HTML element and dropdown need to be wrapped in the class `.slds-drop
 
 The main thing that distinguishes menus from other popover blocks is keyboard navigation: elsewhere, users press the Tab key to navigate through actionable items, but in a menu, users press the arrow keys to navigate.
 
-- Arrow keys cycle focus through menu items (you should use JavaScript to disable focus for any disabled items)
+- Arrow keys cycle focus through menu items (including disabled menu items)
 - If a menu item opens a submenu, pressing Enter or the right arrow key opens the submenu and focus goes to the first item in the submenu
 - If a submenu is open, pressing the left arrow key closes the submenu and puts focus back on the menu item that opened the submenu
 - Tab key closes the menu and moves focus to the next focusable element on the page