container to the next/previous workspace and +move container to workspace current+
(the last one makes sense only when used with criteria).
++workspace next+ cycles through either numbered or named workspaces. But when it
+reaches the last numbered/named workspace, it looks for named workspaces after
+exhausting numbered ones and looks for numbered ones after exhausting named ones.
+
See <<move_to_outputs>> for how to move a container/workspace to a different
RandR output.