Allow HTML in keyboard shortcut menus

[trichoplax]

Is your feature request related to a problem? Please describe.
The keyboard shortcut menus are currently text-only, which involves using ====== instead of accessible separators such as <hr> or an HTML table. This makes the shortcut menus unlikely to work well with assistive technologies such as screen readers.

Describe the solution you'd like
The keyboard shortcut menus could be HTML rather than text-only.