"Templates" are a feature of vSphere vCenter together with cloning and much more. You need to deploy vCenter (as VCSA and not the Windows version anymore) and point your browser to the vCenter and NOT directly to the Host.
About the manual entry you are referring to. The "vSphere WebClient" is the GUI when using your Browser and connecting to vCenter. Its the old flash based browser GUI. There is the new vSphere Client (HTML5) GUI as well.
You are connected to the GUI named Host Client when using directly a Host.