man: options: hint to cycling of program property.

Very helpful to switch between the different programs
on a transponder in full-transponder-mode for DVB.

DOCS/man/options.rst

@@ -3374,6 +3374,8 @@ DVB
     on a single transponder, or to work around issues in the ``channels.conf``.
     It is also recommended to use this for channels which switch PIDs
     on-the-fly, e.g. for regional news.
+    Switching between the programs is possible by cycling the program
+    property.
 
     Default: ``no``