Reverted removal of version

It seems like this one was missed when reverting the change. For the
discussion, see symfony#4290

cookbook/bundles/best_practices.rst

@@ -224,7 +224,7 @@ following standardized instructions in your ``README.md`` file.
     following command to download the latest stable version of this bundle:
 
     ```bash
-    $ composer require <package-name>
+    $ composer require <package-name> "~1"
     ```
 
     This command requires you to have Composer installed globally, as explained
@@ -259,6 +259,9 @@ following standardized instructions in your ``README.md`` file.
     }
     ```
 
+This template assumes that your bundle is in its ``1.x`` version. If not, change
+the ``"~1"`` installation version accordingly (``"~2"``, ``"~3"``, etc.)
+
 Optionally, you can add more installation steps (*Step 3*, *Step 4*, etc.) to
 explain other required installation tasks, such as registering routes or
 dumping assets.