Digital signature in gemini pages

[Stephane Bortzmeyer]

On Wed, Feb 17, 2021 at 10:35:02PM +0100,
 Christophe HENRY <listes at sbgodin.fr> wrote 
 a message of 39 lines which said:

> Is there a way to set up pages that are signed with Gnupg?

Note that the Web does not have it. (Only channel security, through
TLS, not actual object/data security.) It would be nice for Gemini to
have features missing in the Web :-)

> The purpose is to make pages downloadable along with their source
> code and signature.

May be a convention:

$URL + ".asc" MAY give you access to a signature of $URL?