bug#50804: Command substitutions for keys without keymaps

[Eli Zaretskii]

> From: Stefan Kangas <stefan@marxist.se>
> Date: Mon, 22 Nov 2021 06:48:29 +0100
> Cc: 50804@debbugs.gnu.org
> 
> Lars Ingebrigtsen <larsi@gnus.org> writes:
> 
> > Makes sense to me.
> 
> Thanks, pushed (commit 1aef1a6673).

The NEWS entry says:

  ** New substitution in docstrings and 'substitute-command-keys'.
  Use "\\`KEYSEQ'" to insert a literal key sequence "KEYSEQ"
  (e.g. "C-k") in a docstring or when calling 'substitute-command-keys',

Shouldn't that be "\\`C-k" instead?