Fix some code block styles & lost code block in docs

Author: bocharsky-bw

src/LiveComponent/doc/index.rst

@@ -3100,17 +3100,12 @@ Add a Hook on LiveProp Update
 
 If you want to run custom code after a specific LiveProp is updated,
 you can do it by adding an ``onUpdated`` option set to a public method name
-on the component:
-
-.. code-block:: diff
-
-    // ...
+on the component::
 
     #[AsLiveComponent]
     class ProductSearch
     {
-      - #[LiveProp(writable: true)]
-      + #[LiveProp(writable: true, onUpdated: 'onQueryUpdated')]
+        #[LiveProp(writable: true, onUpdated: 'onQueryUpdated')]
         public string $query = '';
 
         // ...
@@ -3121,17 +3116,14 @@ on the component:
             // and its previous value is passed as an argument
         }
     }
-}
 
-As soon as the `query` LiveProp is updated, the ``onQueryUpdated()`` method
+As soon as the ``query`` LiveProp is updated, the ``onQueryUpdated()`` method
 will be called. The previous value is passed there as the first argument.
 
 If you're allowing object properties to be writable, you can also listen to
-the change of one specific key:
+the change of one specific key::
 
-.. code-block::
-
-    // ...
+    use App\Entity\Post;
 
     #[AsLiveComponent]
     class EditPost