Added update function stub

src/FileHandler.py

@@ -14,6 +14,9 @@ def read_json() -> dict:
     except:
         print("Could not find or read file.")
 
+def update_json(meals: dict):
+    print("TODO: Add update logic")
+
 def get_selected_meals(meals: dict) -> dict:
     meal_json = read_json()
     selected_meals = {}