add direct pointers to the ganeti page

tsa/howto/new-machine.mdwn

@@ -20,8 +20,10 @@ release, testing. Here are site-specific installs:
 
 * [[new-machine-hetzner-cloud]]
 * [[new-machine-hetzner-robot]]
-* for a new machine in the [[ganeti]] cluster, see the [[ganeti]]
-  configuration, "Adding a new instance" section
+* for a new virtual machine in the [[ganeti]] cluster, follow
+  [[ganeti#Adding a new instance]]. new ganeti *nodes* (which host
+  virtual machines) should be installed by following the other
+  procedures here, then [[ganeti#New_node]]
 * linaro: [[openstack]]
 
 The following sites are not documented yet: