The plugin somehow depends on [[mdwn]].  If you have
disabled [[mdwn]], to get [[shortcut]] work, you need
commit in a shortcuts.ext (ext is `rcs|creole|html|txt|etc`).

Then edit the following lines in [[shortcut]] plugin source:

    my $srcfile=srcfile("shortcuts.mdwn", 1);

and

    error(gettext("shortcut plugin will not work without a shortcuts.mdwn"));


(It is better to edit a local copy of shortcut.pm in, say, ~/.ikiwiki/IkiWiki/Plugin
and add ~/.ikiwiki to libdir in your ikiwiki.setup than edit the shortcut.pm installed
in system directly.)