Clarify and expand "create a new bundle" documentation

Rewrote the "create a new bundle" guide for clarity and completeness. Added detailed steps for creating a bundle class, registering namespaces in `composer.json`, updating configuration files, and dumping autoload. These changes aim to make the instructions easier to follow for new developers.

docs/source/development/create-a-new-bundle.rst

@@ -11,24 +11,77 @@
 Create a new bundle
 *******************
 
-Create your own bundle is not a trivial task.
-
-The easiest way to achieve this is seems to be : 
-
-1. Prepare a fresh installation of the chill project, in a new directory
-2. Create a new bundle in this project, in the src directory
-3. Initialize a git repository **at the root bundle**, and create your initial commit.
-4. Register the bundle with composer/packagist. If you do not plan to distribute your bundle with packagist, you may use a custom repository for achieve this [#f1]_
-5. Move to a development installation, made as described in the :ref:`installation-for-development` section, and add your new repository to the composer.json file
-6. Work as :ref:`usual <editing-code-and-commiting>`
-
 .. warning::
 
     This part of the doc is not yet tested
 
-TODO
+Create a new directory with Bundle class
+----------------------------------------
+
+.. code-block:: bash
+
+   mkdir -p src/Bundle/ChillSomeBundle/src
+
+Add a bundle file
+
+.. code-block:: php
+
+    <?php
+
+    declare(strict_types=1);
+
+    /*
+     * Chill is a software for social workers
+     *
+     * For the full copyright and license information, please view
+     * the LICENSE file that was distributed with this source code.
+     */
+
+    namespace Chill\SomeBundle;
+
+    use Symfony\Component\HttpKernel\Bundle\Bundle;
+
+    class ChillSomeBundle extends Bundle {}
+
+Register the new psr-4 namespace
+--------------------------------
+
+In composer.json, add the new psr4 namespace
+
+.. code-block:: diff
+
+    {
+    "autoload": {
+        "psr-4": {
+    +        "Chill\\SomeBundle\\": "src/Bundle/ChillSomeBundle/src",
+        }
+    }
+    }
 
 
-.. rubric:: Footnotes
+Register the bundle
+-------------------
+
+Register in the file :code:`config/bundles.php`:
+
+.. code-block:: php
+    Vendor\Bundle\YourBundle\YourBundle::class => ['all' => true],
+
+Add the doctrine_migration namespace
+------------------------------------
+
+Add the namespace to :code:`config/packages/doctrine_migrations_chill.yaml`
+
+.. code-block:: diff
+
+   doctrine_migrations:
+       migrations_paths:
+   +        'Chill\Some\Ticket': '@ChillSomeBundle/migrations'
+
+Dump autoloading
+----------------
+
+.. code-block:: bash
+
+   symfony composer dump-autoload
 
-.. [#f1] Be aware that we use the Affero GPL Licence, which ensure that all users must have access to derivative works done with this software.