fix (#1227)

Author: zhangenming

content/en/guide/v10/signals.md

@@ -429,7 +429,7 @@ const count = signal(0);
 effect(() => {
   // Update `count` without subscribing to `count` or `delta`:
   count.value = untracked(() => {
-    count.value + delta.value
+    return count.value + delta.value
   });
 });
 ```

content/ru/guide/v10/signals.md

@@ -409,7 +409,7 @@ const count = signal(0);
 effect(() => {
   // Обновляем `count` без подписки на `count` или `delta`:
   count.value = untracked(() => {
-    count.value + delta.value
+    return count.value + delta.value
   });
 });
 ```