Update references to current branch

E.g. changed "2.2" to "2.3" and so on

Author: garak

contributing/documentation/overview.rst

@@ -13,7 +13,7 @@ Before contributing, you need to become familiar with the :doc:`markup
 language <format>` used by the documentation.
 
 The Symfony2 documentation is hosted on GitHub:
-
+2
 .. code-block:: text
 
  https://github.com/symfony/symfony-docs
@@ -29,17 +29,17 @@ Consistent with Symfony's source code, the documentation repository is split int
 multiple branches, corresponding to the different versions of Symfony itself.
 The ``master`` branch holds the documentation for the development branch of the code.
 
-Unless you're documenting a feature that was introduced *after* Symfony 2.2
-(e.g. in Symfony 2.3), your changes should always be based on the 2.2 branch.
-To do this checkout the 2.2 branch before the next step:
+Unless you're documenting a feature that was introduced *after* Symfony 2.3
+(e.g. in Symfony 2.4), your changes should always be based on the 2.3 branch.
+To do this checkout the 2.3 branch before the next step:
 
 .. code-block:: bash
 
- $ git checkout 2.2
+ $ git checkout 2.3
 
 .. tip::
 
- Your base branch (e.g. 2.2) will become the "Applies to" in the :ref:`doc-contributing-pr-format`
+ Your base branch (e.g. 2.3) will become the "Applies to" in the :ref:`doc-contributing-pr-format`
  that you'll use later.
 
 Next, create a dedicated branch for your changes (for organization):
@@ -57,17 +57,17 @@ Creating a Pull Request
 Following the example, the pull request will default to be between your
 ``improving_foo_and_bar`` branch and the ``symfony-docs`` ``master`` branch.
 
-If you have made your changes based on the 2.2 branch then you need to change
-the base branch to be 2.2 on the preview page by clicking the ``edit`` button
+If you have made your changes based on the 2.3 branch then you need to change
+the base branch to be 2.3 on the preview page by clicking the ``edit`` button
 on the top left:
 
 .. image:: /images/docs-pull-request-change-base.png
  :align: center
 
 .. note::
 
- All changes made to a branch (e.g. 2.2) will be merged up to each "newer"
- branch (e.g. 2.3, master, etc) for the next release on a weekly basis.
+ All changes made to a branch (e.g. 2.3) will be merged up to each "newer"
+ branch (e.g. 2.4, master, etc) for the next release on a weekly basis.
 
 GitHub covers the topic of `pull requests`_ in detail.