Within an Info window, pressing a single digit, (such as ‘1’),
selects that menu item, and places its node in the current window.
For convenience, there is one exception; pressing ‘0’ selects the
last item in the node’s menu. When ‘--vi-keys’ is in
effect, digits set the numeric argument, so these commands are remapped
to their ‘M-’ varieties. For example, to select the last menu
item, press M-0.