[[ https://www.w3.org/TR/wai-aria-practices/examples/menu-button/menu-button-links.html#kbd2_label.html | w3 recommends that dropdown menus respond to numerous keys that Vector doesn't currently support
]]. They recommend including the following keyboard support:
1) up/down keys should move focus around the menu items
2) escape key should close the menu
3) home key moves focus to first menu item
4) end key moves focus to last menu item
5) a-z moves focus to menu item that starts with typed character
Vector has several dropdown menus that do not meet this criteria:
1) The user menu
2) The language variants tab menu
3) The "More" tab menu
For example, the user menu doesn't respond to up/down key navigation:
{F34707444}
=== Acceptance Criteria
[] Dropdown menus in Vector respond to the keys listed by w3's "Menu" and "Menu Button" tables