enforce windows terminal mode to basic, warning message (#77)

Types.hs

@@ -1,3 +1,5 @@
+{-# LANGUAGE LambdaCase #-}
+
 module Types where
 
 import Data.ByteString.Char8 (ByteString)
@@ -5,3 +7,9 @@ import Data.ByteString.Char8 (ByteString)
 newtype Contact = Contact {toBs :: ByteString}
 
 data TermMode = TermModeBasic | TermModeSimple | TermModeEditor deriving (Eq)
+
+termModeName :: TermMode -> String
+termModeName = \case
+  TermModeBasic -> "basic"
+  TermModeSimple -> "simple"
+  TermModeEditor -> "editor"