Minor gramatical error in attrs.md (#1873)

Author: mst101

src/guide/components/attrs.md

@@ -177,7 +177,7 @@ export default {
 }
 ```
 
-Note that although the `attrs` object here always reflect the latest fallthrough attributes, it isn't reactive (for performance reasons). You cannot use watchers to observe its changes. If you need reactivity, use a prop. Alternatively, you can use `onUpdated()` to perform side effects with latest `attrs` on each update.
+Note that although the `attrs` object here always reflects the latest fallthrough attributes, it isn't reactive (for performance reasons). You cannot use watchers to observe its changes. If you need reactivity, use a prop. Alternatively, you can use `onUpdated()` to perform side effects with latest `attrs` on each update.
 
 </div>