Add note to README

Author: WesCossick

README.md

@@ -48,7 +48,8 @@ Done!
 ## Accessibility notes
 Our team carefully studied and adhered to [Web Content Accessibility Guidelines 2.1](https://www.w3.org/WAI/standards-guidelines/wcag/) and  [WAI-ARIA Authoring Practices 1.1](https://www.w3.org/TR/wai-aria-practices/) when designing this Hook. Here are some facets of accessibility that are handled automatically:
 
-- Strict adherence to the best practices for menus ([WAI-ARIA: 3.15](https://www.w3.org/TR/wai-aria-practices/#menu))
+- Careful following of the best practices for menus ([WAI-ARIA: 3.15](https://www.w3.org/TR/wai-aria-practices/#menu))
+  - The only deviation is that the first menu item is only focused when the menu is revealed via the keyboard ([see why](https://github.com/sparksuite/react-accessible-dropdown-menu-hook/pull/63))
 - Strict adherence to the best practices for menu buttons ([WAI-ARIA: 3.16](https://www.w3.org/TR/wai-aria-practices/#menubutton))
 - Full keyboard accessibility ([WCAG: 2.1](https://www.w3.org/WAI/WCAG21/quickref/#keyboard-accessible))
 - Use of ARIA properties and roles to establish relationships amongst elements ([WCAG: 1.3.1](https://www.w3.org/WAI/WCAG21/quickref/#info-and-relationships))