docs: improve installation

user_guide_src/source/installation/installing_composer.rst

@@ -7,9 +7,9 @@ Composer Installation
 
 Composer can be used in several ways to install CodeIgniter4 on your system.
 
-The first two techniques describe creating a skeleton project
+The first technique describes creating a skeleton project
 using CodeIgniter4, that you would then use as the base for a new webapp.
-The third technique described below lets you add CodeIgniter4 to an existing
+The second technique described below lets you add CodeIgniter4 to an existing
 webapp,
 
 .. note:: If you are using a Git repository to store your code, or for
@@ -27,8 +27,8 @@ the latest released version of the framework.
 This installation technique would suit a developer who wishes to start
 a new CodeIgniter4 based project.
 
-Installation & Set Up
----------------------
+Installation
+------------
 
 In the folder above your project root::
 
@@ -52,7 +52,11 @@ A sample such installation command, using the default project-root "appstarter":
 
     > composer create-project codeigniter4/appstarter --no-dev
 
-After installation you should follow the steps in the "Upgrading" section.
+Initial Configuration
+---------------------
+
+After installation, a few initial configurations are required.
+See :ref:`initial-configuration` for the details. 
 
 .. _app-starter-upgrading:
 
@@ -126,6 +130,9 @@ The same `CodeIgniter 4 framework <https://github.com/codeigniter4/framework>`_
 repository described in "Manual Installation" can also be added to an
 existing project using Composer.
 
+Installation
+------------
+
 Develop your app inside the ``app`` folder, and the ``public`` folder
 will be your document root.
 
@@ -136,8 +143,8 @@ In your project root::
 As with the earlier two composer install methods, you can omit installing
 phpunit and its dependencies by adding the ``--no-dev`` argument to the ``composer require`` command.
 
-Set Up
-------
+Setting Up
+----------
 
 Copy the ``app``, ``public``, and ``writable`` folders from ``vendor/codeigniter4/framework``
 to your project root
@@ -148,6 +155,12 @@ Copy the ``env``, ``phpunit.xml.dist`` and ``spark`` files, from
 You will have to adjust the system path to refer to the vendor one, e.g., ``ROOTPATH . '/vendor/codeigniter4/framework/system'``,
 - the ``$systemDirectory`` variable in **app/Config/Paths.php**
 
+Initial Configuration
+---------------------
+
+A few initial configurations are required.
+See :ref:`initial-configuration` for the details.
+
 .. _adding-codeigniter4-upgrading:
 
 Upgrading

user_guide_src/source/installation/installing_manual.rst

@@ -26,32 +26,33 @@ and extract it to become your project root.
     The symbols that can be used are ``/``, ``_``, ``.``, ``:``, ``\`` and space.
     So if you install CodeIgniter under the folder that contains the special characters like ``(``, ``)``, etc., CodeIgniter won't work.
 
-Setting Up
-----------
+Initial Configuration
+=====================
 
-None
+After installation, a few initial configurations are required.
+See :ref:`initial-configuration` for the detail.
 
 .. _installing-manual-upgrading:
 
 Upgrading
----------
+=========
 
 Download a new copy of the framework, and then replace the ``system`` folder.
 
 Read the :doc:`upgrade instructions <upgrading>`, and check Breaking Changes and Enhancements.
 
 Pros
-----
+====
 
 Download and run
 
 Cons
-----
+====
 
 You are responsible for merge conflicts when updating
 
 Structure
----------
+=========
 
 Folders in your project after set up:
 app, public, system, writable

user_guide_src/source/installation/running.rst

@@ -12,24 +12,31 @@ This section addresses how to use each technique, and explains some of the pros
 If you're new to CodeIgniter, please read the :doc:`Getting Started </intro/index>`
 section of the User Guide to begin learning how to build dynamic PHP applications. Enjoy!
 
-Initial Configuration & Set Up
-==============================
+.. _initial-configuration:
+
+Initial Configuration
+=====================
 
 #. Open the **app/Config/App.php** file with a text editor and
-   set your base URL. If you need more flexibility, the baseURL may
+   set your base URL to ``$baseURL``. If you need more flexibility, the baseURL may
    be set within the **.env** file as ``app.baseURL = 'http://example.com/'``.
    (Always use a trailing slash on your base URL!)
+
+    .. note:: If you don't set the ``baseURL`` correctly, in development mode,
+        the debug toolbar may not load properly and web pages may take considerably
+        longer to display.
+
 #. If you intend to use a database, open the
    **app/Config/Database.php** file with a text editor and set your
    database settings. Alternately, these could be set in your **.env** file.
 #. If it is not on the production server, set ``CI_ENVIRONMENT`` to ``development``
    in **.env** file to take advantage of the debugging tools provided. See
    :ref:`setting-development-mode` for the detail.
 
-.. important:: In production environments, you should disable error display and
-    any other development-only functionality. In CodeIgniter, this can be done
-    by setting the environment to "production". By default, the application will
-    run using the "production" environment. See also :ref:`environment-constant`.
+    .. important:: In production environments, you should disable error display and
+        any other development-only functionality. In CodeIgniter, this can be done
+        by setting the environment to "production". By default, the application will
+        run using the "production" environment. See also :ref:`environment-constant`.
 
 .. note:: If you will be running your site using a web server (e.g., Apache or Nginx),
     you will need to modify the permissions for the ``writable`` folder inside