Allow 0 for shopping list item amounts (references #2712)

changelog/81_UNRELEASED_xxxx-xx-xx.md

@@ -0,0 +1,57 @@
+> ⚠️ xxxBREAKING CHANGESxxx
+
+> ❗ xxxImportant upgrade informationXXX
+
+> 💡 xxxMinor upgrade informationXXX
+
+### New Feature: xxxx
+
+- xxx
+
+### Stock
+
+- xxx
+
+### Shopping list
+
+- An amount of `0` is now allowed for shopping list items (just a convenience optimization, it was already possible to leave the amount field empty which implicitly resulted in an amount of `0`)
+
+### Recipes
+
+- xxx
+
+### Meal plan
+
+- xxx
+
+### Chores
+
+- xxx
+
+### Calendar
+
+- xxx
+
+### Tasks
+
+- xxx
+
+### Batteries
+
+- xxx
+
+### Equipment
+
+- xxx
+
+### Userfields
+
+- xxx
+
+### General
+
+- xxx
+
+### API
+
+- xxx