avoids qunaitities < 0 in add dialog

src/components/AddDialog/AddDialog.js

@@ -28,6 +28,7 @@ const AddDialog = ({ name, quantity, isOpen, handleClose, handleCancel, handleAd
               id="quantity"
               label="Quantity"
               type="number"
+              InputProps={{ inputProps: { min: 0} }}
               value={quantity}
               onChange={(event) => updateQuantity(event.target.value)}
             />