add feedback.yaml

.build-all.dhall

+let Prelude =
+        env:DHALL_PRELUDE
+      ? https://raw.githubusercontent.com/dhall-lang/dhall-lang/v20.1.0/Prelude/package.dhall
+          sha256:26b0ef498663d269e4dc6a82b0ee289ec565d683ef4c00d0ebdd25333a5a3c98
+
+let H = ./horizon-spec.dhall
+
+let toStep
+    : Text → Text
+    = \(x : Text) -> ".#${x}"
+
+let input = Prelude.Map.keys Text H.HaskellPackage.Type ./horizon.dhall
+
+let packages =
+      Prelude.List.map
+        Text
+        Text
+        toStep 
+        (input : List Text)
+
+in  "nix build -L" ++ Prelude.List.fold Text packages Text (\(x : Text) -> \(y : Text) -> x ++ " " ++ y) ""

feedback.yaml

+loops:
+  build: cat .build-all.dhall | dhall text | bash
+  check: nix flake check -L