Add docs for embedded tag

Author: WebMamba

src/TwigComponent/doc/index.rst

@@ -906,6 +906,26 @@ should be compiled by Twig
 
     // and pass object, or table, or anything you imagine
     <twig:Alert :foo="['col' => ['foo', 'oof']]"/>
+    
+This syntax came also with special syntax for embedded component
+
+.. code-block:: html+twig
+    
+    <twig:Alert message="hello" :user="user.id">
+        <twig:block name="footer">
+            ...
+        </twig:block>
+    </twig:Alert>
+    
+And in your component template you can access your embedded block
+
+.. code-block:: html+twig
+    
+    <div class="content">
+         {% block footer %}
+            ...
+         {% block footer %}
+     </div>
 
 You can pass content directly inside your component.