docs: Add upgrade note

Author: neznaika0

user_guide_src/source/installation/installing_composer.rst

@@ -191,11 +191,11 @@ Next Minor Version
 If you want to use the next minor version branch, after using the ``builds`` command
 edit **composer.json** manually.
 
-If you try the ``4.7`` branch, change the version to ``4.7.x-dev``::
+If you try the ``4.8`` branch, change the version to ``4.8.x-dev``::
 
     "require": {
         "php": "^8.2",
-        "codeigniter4/codeigniter4": "4.7.x-dev"
+        "codeigniter4/codeigniter4": "4.8.x-dev"
     },
 
 And run ``composer update`` to sync your vendor

user_guide_src/source/installation/upgrading.rst

@@ -7,6 +7,12 @@ upgrading from.
 
 See also :doc:`./backward_compatibility_notes`.
 
+The manual mentions changes to **project space**. To perform the update,
+you need to compare the original files from **vendor/codeigniter4/framework** or from the ZIP archive and make changes.
+
+Example, the original **app/Config/App.php** will be located in **vendor/codeigniter4/framework/app/Config/App.php**.
+Alternatively, replace it with a new file and add your previous lines.
+
 .. note:: If you don't know what version of CodeIgniter you are currently running,
     you can get it from :ref:`the Debug Toolbar <the-debug-toolbar>`,
     or simply echo the constant ``\CodeIgniter\CodeIgniter::CI_VERSION``.