Possibly outdated documentation for agents templates with satellites

[julianbrost]

A customer as part of a support ticket:

I noticed that the documentation for deploying agents with Icinga Director still advises creating a template per satellite zone:

icingaweb2-module-director/doc/24-Working-with-agents.md

Lines 21 to 24 in 52a7584

	As long as you're not using Satellite nodes, a single Agent zone is all
	you need. Otherwise, you should create one Agent template per satellite
	zone. If you want to move an Agent to a specific zone, just assign it
	the correct template and you're all done.

while the release notes for version 1.3.0 suggest this is no longer necessary.

icingaweb2-module-director/doc/82-Changelog.md

Lines 1289 to 1291 in 52a7584

	* It is now possible to set Agent and Zone settings on every single host. This
	means that you no longer need to provide dedicated Templates for Satellite
	nodes

I'm not entirely sure if that's just outdated or possibly still the recommended way even though it's not necessary anymore. I'm just passing this on so that someone more involved in Director can assess this.

ref/IP/61961 (mostly not related to this issue, this just came up as part of that ticket)