I followed instructions at 

    http://ikiwiki.info/plugins/po/

and added to `configfile`

        po_master_language => 'en|English',
	po_slave_languages => [ 'zh|Chinese' ],
        po_translatable_pages => '(* and !*/Discussion and !blog/*/comment_*)',
        po_link_to => 'current'

and did 

      ikiwiki --setup configfile

But I don't seem to see any change in the newly built site. 

How do I actually use po to create translation pages? 

1) I have existing pages that's in English. How do I add translated versions of some of those pages in the slave language?

2) How do I add new pages with the primary language version and alternative versions in slave languages?

The documentation of po is not explicit with what are the concrete steps.