update Modifying values in arrays / Appending new values simplify. (#1189)

Author: mizulu

src/routes/concepts/stores.mdx

@@ -253,8 +253,8 @@ Instead of relying on discovering individual indices, path syntax introduces sev
 
 ### Appending new values
 
-To append a new element to an array within a store, you specify the target array and set the index to the desired position.
-For example, if you wanted to append the new element to the end of the array, you would set the index to `array.length`:
+To append new values to an array in a store, use the setter function with the spread operator (`...`) to create a new array that includes the existing items and the new ones.
+For appending a single element, you can instead leverage the "path syntax" by specifying the array’s length as the index to set.
 
 ```jsx
 setStore("users", (otherUsers) => [