docs: fix list of new symbols in index page
docs: fix list of new symbols in index page

For some reason, there is no link created for the "new symbols" pages,
but it seems glib docs either.

Signed-off-by: Marc-André Lureau <a6f2b960a4aca61381fc650a67901b2ac8e83e6d@redhat.com>

GNOME/gcab,GNOME/gcab