fix slice() link (#4156)

beta/src/pages/learn/updating-arrays-in-state.md

@@ -35,7 +35,7 @@ Alternatively, you can [use Immer](#write-concise-update-logic-with-immer) which
 
 <Gotcha>
 
-Unfortunately, [`slice`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/splice) and [`splice`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/splice) are named similarly but are very different:
+Unfortunately, [`slice`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/slice) and [`splice`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/splice) are named similarly but are very different:
 
 * `slice` lets you copy an array or a part of it.
 * `splice` **mutates** the array (to insert or delete items).