Dead chat will get announcements when someone joins or leaves it.

This is mainly for wizard and cult rounds, where it is important to know that a wizard/cultist is watching. The announcement was added for most other types of leaving/joining the ghost realm. Admin ghost doesn't get announced for obvious reasons.

code/modules/admin/admin_verbs.dm

@@ -377,7 +377,8 @@ var/list/admin_verbs_mentor = list(
 	else
 		//ghostize
 		var/mob/body = mob
-		body.ghostize(1)
+		var/mob/dead/observer/ghost = body.ghostize(1)
+		ghost.admin_ghosted = 1
 		if(body && !body.key)
 			body.key = "@[key]"	//Haaaaaaaack. But the people have spoken. If it breaks; blame adminbus
 		feedback_add_details("admin_verb","O") //If you are copy-pasting this, ensure the 2nd parameter is unique to the new proc!