added models

lib/models/ingredient.dart

@@ -0,0 +1,11 @@
+class Ingredient {
+  final String title;
+  List<String> possibleUnits = [];
+  List<String> preferredBrands = [];
+
+  Ingredient({
+    required this.title,
+    required this.possibleUnits,
+    required this.preferredBrands,
+  });
+}

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 }

lib/models/steps.dart

@@ -0,0 +1,13 @@
+/// Used to display the steps required to cook the referenced recipe
+class Steps {
+  final List<CookingStep> steps = [];
+
+  void add(CookingStep step) => steps.add(step);
+}
+
+class CookingStep {
+  final String title;
+  final String description;
+
+  CookingStep({required this.title, this.description = ''});
+}