(Kor) WIP: First draft of Korean RG.

Not at all correct, just a minimal implementation that compiles.

src/korean/ExtendKor.gf

@@ -0,0 +1,8 @@
+--# -path=.:../common:../abstract
+
+concrete ExtendKor of Extend = CatKor
+  -- ** ExtendFunctor - []
+  -- with (Grammar=GrammarKor)
+  ** open Prelude, ResKor, NounKor in {
+
+} ;