Add Korean language pack with the minimal set of translation. This work will...

Add Korean language pack with the minimal set of translation. This work will make the UI usuable enough for the Koreans who do not understand English so that I expect more Korean people will consider to join which will definitely help the growth of Steemit.

The entire translation will be done with the Korean community members. Our community will co-work to make the translation as fluent as possible.

From @asbear