adding haskell template providing dev/prod environments

flake.nix

@@ -71,6 +71,11 @@
           bindings = bindingsOverlay;
         };
 
+        templates = {
+          hs-bindings = ./nix/templates/haskell;
+          description = "Haskell Bindings to p2prc protocol";
+        };
+
       }
     ));
 }