doc: fix "First name" described in news
doc: fix "First name" described in news

See [groonga-dev,00971] Re: [ANN] mroonga 2.04
Reported by Kazuhiro Isobe

naoa/mroonga,yoku0825/mroonga,yoku0825/mroonga,yoku0825/mroonga,naoa/mroonga,naoa/mroonga,yoku0825/mroonga,mroonga/mroonga,naoa/mroonga,mroonga/mroonga,mroonga/mroonga,yoku0825/mroonga,yoku0825/mroonga,mroonga/mroonga,naoa/mroonga,naoa/mroonga