In the platforms list, update the link to the ia64 project pages. The
ia64 project pages live under the ia64 subdirectory, with index.html
the main page. The link was pointing to the old page, which tells you
to update your bookmark. While here, spell IA64 as IA-64. This is
consistent with the spelling in the "What is FreeBSD?" paragraph and
also with the spelling in the project pages.