BF: CS-1715: document that advance reservations can only be submitted from a submit host

Author: ernst-bablick

doc/markdown/man/man1/qrdel.md

@@ -27,6 +27,8 @@ Only if all jobs referring to an AR are removed from the xxQS_NAMExx database wi
 `Qrdel` deletes ARs in the order in which the AR identifiers are presented. Find additional information 
 concerning *wc_user_list* and *wc_ar_list* in xxqs_name_sxx_types(1).
 
+`Qrdel` operations can only be executed from submit hosts.
+
 # OPTIONS
 
 ## -f  

doc/markdown/man/man1/qrsub.md

@@ -32,6 +32,8 @@ ARs will be deleted either automatically when the end time is reached, or manual
 first all jobs requesting the AR will be removed and then AR itself. Already granted ARs can be shown
 with `qrstat`.
 
+`Qrsub` and `qrdel` operations can only be executed from submit hosts.
+
 Note: To make AR behavior predictable, it is necessary to have reserved resources available at the time of AR start. 
 This is done by keeping jobs with an unlimited runtime limit separated from ARs, and not considering resources used 
 by such jobs for reservation.