Add sas private repo requirements

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

hosts/elara/users/nikara/default.nix

@@ -65,6 +65,10 @@ in
     (import ../../../common/configs/user/gui/wev { inherit user home; })
     (import ../../../common/configs/user/gui/x11 { inherit user home; })
     (import ../../../common/configs/user/gui/xdg { inherit user home; })
+
+    # Warning: the following imports use private SAS repositories.
+    # You must build the system once with these imports commented out,
+    # then uncomment them and rebuild the system once keys are provisioned.
   ];
 
   # echo "password" | mkpasswd -s