docs: say thanks to the Korean translator, and trim a double space

THANKS

@@ -11,6 +11,7 @@ Mario Blättermann <mario.blaettermann@gmail.com>      German
 Ricardo Cárdenes Medina <ricardo@conisys.com>         Spanish
 Antonio Ceballos <aceballos@gmail.com>                Spanish
 Wei-Lun CHAO <chaoweilun@pcmail.com.tw>               Chinese (traditional)
+Seong-ho Cho <darkcircle.0426@gmail.com>              Korean
 Yuri Chornoivan <yurchor@ukr.net>                     Ukrainian
 Marco Colombo <magicdice@inwind.it>                   Italian
 Mihai Cristescu <mihai.cristescu@archlinux.info>      Romanian