add 'D' motion, which does the same thing as 'd$' (these two aliases exist in Vim too, to do the same thing)

fcore/normal-mode/normal-mode.sml

@@ -194,6 +194,7 @@ struct
         if String.size str = 0 then NormalMove.moveToEnd app
         else NormalMove.moveToLine (app, count)
     | #"%" => NormalMove.moveToMatchingPair app
+    | #"D" => NormalDelete.deleteToEndOfLine (app, time)
     | #"x" => NormalDelete.removeChr (app, count, time)
     | #"J" => NormalDelete.removeLineBreaks (app, count, time)
     | #"/" => switchToNormalSearchMode (app, false)

todo.md

@@ -16,4 +16,4 @@
   - They should search for the next char in the specific pair, the same way in Vim
   - Add tests for both
 
-Afterwards, add tests for yanking.
+  Afterwards, add tests for yanking.