Document John's modifications to bulk commands

doc/org.texi

@@ -7957,7 +7957,8 @@ Jump to the running clock in another window.
 @cindex remote editing, bulk, from agenda
 
 @orgcmd{m,org-agenda-bulk-mark}
-Mark the entry at point for bulk action.
+Mark the entry at point for bulk action.  With prefix arg, mark that many
+successive entries.
 @c
 @orgcmd{u,org-agenda-bulk-unmark}
 Unmark entry for bulk action.
@@ -7983,6 +7984,7 @@ t  @r{Change TODO state.  This prompts for a single TODO keyword and}
 s  @r{Schedule all items to a new date.  To shift existing schedule dates}
    @r{by a fixed number of days, use something starting with double plus}
    @r{at the prompt, for example @samp{++8d} or @samp{++2w}.}
+S  @r{Reschedule randomly by N days.  N will be prompted for.}
 d  @r{Set deadline to a specific date.}
 @end example