docs(set): update example to correctly handle numeric keys as object properties

Author: nightohl

docs/object/set.mdx

@@ -16,4 +16,7 @@ set({}, 'name', 'ra')
 
 set({}, 'cards[0].value', 2)
 // => { cards: [{ value: 2 }] }
+
+set({}, 'user.1083.name', 'Alice')
+// => { user: { "1083": { name: 'Alice' } } }
 ```