Add Korean localization (#537)

Sources/Secretive.xcodeproj/project.pbxproj

@@ -434,6 +434,7 @@
 				de,
 				"pt-BR",
 				fi,
+				ko,
 			);
 			mainGroup = 50617D7623FCE48D0099B055;
 			productRefGroup = 50617D8023FCE48E0099B055 /* Products */;