minor #507 [LiveComponent] Fix code block language in docs (HypeMC)

This PR was merged into the 2.x branch.

Discussion
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[LiveComponent] Fix code block language in docs

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| Tickets       | -
| License       | MIT

Fixes incorrect language used in some code blocks.

Commits
-------

bacc8b3 [LiveComponent] Fix code block language in docs

Author: weaverryan

src/LiveComponent/src/Resources/doc/index.rst

@@ -321,7 +321,7 @@ Other times, you might want to update the internal value of a property,
 but wait until later to re-render the component (e.g. until a button is
 clicked). To do that, use ``norender`` modifier:
 
-.. code-block:: diff
+.. code-block:: twig
 
     <input data-model="norender|max">
 
@@ -346,7 +346,7 @@ rely on the ``name`` attribute.
 To activate this, you must add a ``data-model`` attribute to
 the ``<form>`` element:
 
-.. code-block:: diff
+.. code-block:: twig
 
     <div {{ attributes }}>
         <form data-model="*">
@@ -370,7 +370,7 @@ Updating a Model Manually
 You can also change the value of a model more directly, without
 using a form field:
 
-.. code-block:: diff
+.. code-block:: twig
 
     <button
         type="button