Make entry names optional, since notes shouldn't have names and articles should

src/Model/Entry.hs

@@ -0,0 +1,15 @@
+{-# LANGUAGE OverloadedStrings #-}
+module Model.Entry where
+
+import Model ( Entry, entryName, entryContent )
+import Data.Maybe ( fromMaybe )
+
+import qualified Data.Text as T
+
+entryTitle :: Entry -> T.Text
+entryTitle = fromMaybe <$> shorten 30 . entryContent <*> entryName
+
+shorten :: Int -> T.Text -> T.Text
+shorten n t
+  | T.length t > n = flip T.append "..." . T.take (n - 1) $ t
+  | otherwise      = t