Add new Fedora 15 release counter language

[Duy Hùng Trần]

Hello,

I'm really sorry if this mailing list is not a right place to ask about Fedora
15 release counter <http://fedoraproject.org/en/counter>;. The counter is not
available in Vietnamese. How could I help translate?

Thank you :) !

All the best,
TRẦN Duy Hùng
http://www.nguyentieuhau.com/