docs: add sub section titles

Author: kenjis

user_guide_src/source/installation/running.rst

@@ -25,31 +25,44 @@ section of the User Guide to begin learning how to build dynamic PHP application
 Initial Configuration
 *********************
 
-#. Open the **app/Config/App.php** file with a text editor and
-   set your base URL to ``$baseURL``. If you need more flexibility, the baseURL may
-   be set within the :ref:`.env <dotenv-file>` file as ``app.baseURL = 'http://example.com/'``.
-   (Always use a trailing slash on your base URL!)
-
-    .. note:: If you don't set the ``baseURL`` correctly, in development mode,
-        the debug toolbar may not load properly and web pages may take considerably
-        longer to display.
-
-#. If you intend to use a database, open the
-   **app/Config/Database.php** file with a text editor and set your
-   database settings. Alternately, these could be set in your **.env** file.
-#. If it is not on the production server, set ``CI_ENVIRONMENT`` to ``development``
-   in **.env** file to take advantage of the debugging tools provided. See
-   :ref:`setting-development-mode` for the detail.
-
-    .. important:: In production environments, you should disable error display and
-        any other development-only functionality. In CodeIgniter, this can be done
-        by setting the environment to "production". By default, the application will
-        run using the "production" environment. See also :ref:`environment-constant`.
-
-.. note:: If you will be running your site using a web server (e.g., Apache or Nginx),
-    you will need to modify the permissions for the **writable** folder inside
-    your project, so that it is writable by the user or account used by your
-    web server.
+Setting the Base URL of Your Site
+=================================
+
+Open the **app/Config/App.php** file with a text editor and
+set your base URL to ``$baseURL``. If you need more flexibility, the baseURL may
+be set within the :ref:`.env <dotenv-file>` 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.
+
+Configure Database Connection Settings
+======================================
+
+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.
+
+Setting to Development Mode
+===========================
+
+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`.
+
+Setting Writable Folder Permission
+==================================
+
+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
+your project, so that it is writable by the user or account used by your
+web server.
 
 ************************
 Local Development Server