doc: Update bit about SSH in the VM.

* doc/guix.texi (Running Guix in a VM): Remove mentions of 'lsh-server';
mention 'openssh-service-type' and add a cross-reference.
* gnu/system/examples/vm-image.tmpl (services): Add a commented-out line
for 'openssh-service-type'.

doc/guix.texi

@@ -24703,11 +24703,10 @@ network connectivity, for example @command{guix download}.
 
 @cindex SSH
 @cindex SSH server
-To enable SSH inside a VM you need to add a SSH server like @code{(dropbear-service)}
-or @code{(lsh-service)} to your VM.  The @code{(lsh-service}) doesn't currently
-boot unsupervised.  It requires you to type some characters to initialize the
-randomness generator.  In addition you need to forward the SSH port, 22 by
-default, to the host.  You can do this with
+To enable SSH inside a VM you need to add an SSH server like
+@code{openssh-service-type} to your VM (@pxref{Networking Services,
+@code{openssh-service-type}}).  In addition you need to forward the SSH port,
+22 by default, to the host.  You can do this with
 
 @example
 `guix system vm config.scm` -net user,hostfwd=tcp::10022-:22

gnu/system/examples/vm-image.tmpl

@@ -5,7 +5,7 @@
 ;;
 
 (use-modules (gnu) (srfi srfi-1))
-(use-service-modules desktop networking xorg)
+(use-service-modules desktop networking ssh xorg)
 (use-package-modules bootloaders nvi wget xorg)
 
 (define vm-image-motd (plain-file "motd" "
@@ -73,6 +73,9 @@ accounts.\x1b[0m
                             (xorg-configuration
                              (keyboard-layout keyboard-layout)))))
 
+                 ;; Uncomment the line below to add an SSH server.
+                 ;;(service openssh-service-type)
+
                  ;; Use the DHCP client service rather than NetworkManager.
                  (service dhcp-client-service-type))