Bug#992157: release-notes: warn about SSH at the start of the upgrade paragraph

[Justin B Rye <justin.byam.rye@gmail.com>]

Paul Gevers wrote:
>      <title>Minimal system upgrade</title>
> +    <important>
> +      <!-- buster to bullseye -->
> +      <para>
> +        If you upgrade remotely, be aware of <xref linkend="ssh-not-available"/>.
> +      </para>
> +    </important>

Yes, this looks good.  The link text appears as "Section x.y.z, *No
new SSH connections possible during upgrade*", right?

"If you upgrade" might mean "habitually" or "hypothetical future",
which are two things it's reasonable to be ambiguous between here,
though it's possible you might have wanted "If you are upgrading
remotely".
-- 
JBR	with qualifications in linguistics, experience as a Debian
	sysadmin, and probably no clue about this particular package