Please add Korean to Transifex

[kwon0408]

Currently in Transifex, both Korean (ko) and Korean (Korea) (ko_KR) are shown as "pending request to add this language" and nothing further can be performed. If it is to be added, I think just ko will be OK.

Formerly, before Korean was an option in Transifex itself, there was an attempt (#73) to add it to this site, so can we use this as a base?