added models

lib/models/recipe.dart

@@ -0,0 +1,18 @@
+import 'ingredient.dart';
+import 'steps.dart';
+
+class Recipe {
+  final String title;
+  final String description;
+  final Difficulty? difficulty;
+  final List<Ingredient> ingredients = [];
+  final Steps steps = Steps();
+
+  Recipe({
+    required this.title,
+    this.description = '',
+    this.difficulty,
+  });
+}
+
+enum Difficulty { veryEasy, easy, intermediate, hard, veryHard }