Improve server connection documentation
Server connnection documentation is lacking a bit:
- https://www.paraview.org/Wiki/ParaView:Server_Configuration
- https://discourse.paraview.org/t/using-ssh-support-to-secure-your-client-server-communication-with-paraview/682
- (PDF file that I can't find right now, @wascott you shared it I think ?)
Ideally, it should be documented in the paraview docs.