No need to define "cmd-foo" anchors; use :doc:`foo <cmds/foo>`
instead. If we want "cmd-foo" but it should be tested.
See also 38b24c2325 (docs: Use :doc: role when linking to commands,
2022-09-23).
This seems a bit better because it's what bind uses. To makes sure that
something like :kbd:`ctrl-x` looks good in HTML, remove the border from the
kbd style. Else both "ctrl" and "x" get small boxes which looks weird.