Update proofreader.md

doc/development/i18n/proofreader.md

@@ -29,6 +29,7 @@ are very appreciative of the work done by translators and proofreaders!
 - Korean
   - Chang-Ho Cha - [GitLab](https://gitlab.com/changho-cha), [Crowdin](https://crowdin.com/profile/zzazang)
   - Huang Tao - [GitLab](https://gitlab.com/htve), [Crowdin](https://crowdin.com/profile/htve)
+  - Ji Hun Oh - [GitLab](https://gitlab.com/BawAppie), [Crowdin](https://crowdin.com/profile/BawAppie)
 - Polish
   - Filip Mech - [GitLab](https://gitlab.com/mehenz), [Crowdin](https://crowdin.com/profile/mehenz)
 - Portuguese, Brazilian