Add documentation for new courtesy tone (bug #2329)

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@3700 65c4cc65-6c06-0410-ace0-fbb531ad65f3

configs/features.conf.sample

@@ -3,8 +3,11 @@
 ;
 
 [general]
-parkext => 700				; What ext. to dial to park
-parkpos => 701-720			; What extensions to park calls on
-context => parkedcalls			; Which context parked calls are in
-;parkingtime => 45			; Number of seconds a call can be parked for (default is 45 seconds)
+parkext => 700			; What ext. to dial to park
+parkpos => 701-720		; What extensions to park calls on
+context => parkedcalls		; Which context parked calls are in
+;parkingtime => 45		; Number of seconds a call can be parked for 
+				; (default is 45 seconds)
 ;transferdigittimeout => 3	; Number of seconds to wait between digits when transfering a call
+;courtesytone = beep		; Sound file to play to the parked caller 
+				; when someone dials a parked call