Document the domain parameter

morph/lib/customize-issuer.nix

@@ -26,6 +26,13 @@
   # A string giving the VPN IPv4 address for this system.
 , monitoringvpnIPv4
 
+  # A string giving the domain name associated with this grid.  This is meant
+  # to be combined with the hostname for this system to produce a
+  # fully-qualified domain name.  For example, an issuer might have "payments"
+  # as its hostname and belong to a grid with the domain
+  # "example-grid.invalid".  This ``domain`` parameter should have the value
+  # ``"example-grid.invalid"`` for the system figure out that
+  # ``payments.example-grid.invalid`` is the name of this system.
 , domain
 
   # A set mapping usernames as strings to SSH public keys as strings.  For

morph/lib/customize-monitoring.nix

@@ -8,11 +8,10 @@
   # allows Grafana to show us hostnames instead of VPN IP addresses.
   hostsMap
 
-, domain
-
   # See ``customize-issuer.nix``.
 , monitoringvpnKeyDir
 , monitoringvpnIPv4
+, domain
 
   # A list of VPN IP addresses as strings indicating which clients will be
   # allowed onto the VPN.