Rename the main menu disclosure button label to "Menu"

You make a good point. I'm looking at Olivero's menu toggle and they're using "Toggle Menu" as the aria-label and "Menu" as the visible label. I don't think that the word "Toggle" adds anything useful so I'm good with using just "Menu" for the aria-label and the default value for the visible text.

MR sets the aria-label to "Menu" and defaults the visible label (if enabled) to "Menu".