move some stuff to admin and engineering guide - to reduce confusion

docs/admin-guide/ssh_gateways.md

@@ -1,4 +1,4 @@
-# SSH Gateways
+# Admin Guide - SSH Gateways
 
 The purpose of the ssh gateways is to give access to protected networks and resources (for a finite period of time). The gateway always gives access to the networks first name is indicating, i.e. sf-gw is giving access to all sf networks, sls-gw is giving access to sls networks.
 

docs/admin-guide/unix_groups.md

@@ -1,4 +1,4 @@
-# Unix Groups / Group Management
+# Admin Guide - Unix Groups / Group Management
 
 Users can be added to a unix group by this workflow:
 [SSH Gateway - User Guide](https://linux.psi.ch/services-user-guide/unix_groups)

docs/services/admin-guide/index.md

@@ -1 +0,0 @@
-# Admin Guide