docs: update database connection with information on how to connect to a MySQL server over a socket

[tangix]

Description
Added a section on how to connect to a MySQL server over a socket. I'm developing for Google Cloud Run / Cloud SQL and had to use the CodeIgniter source to understand how to connect to the Cloud SQL socket created with --add-cloudsql-instances parameter passed to gcloud deploy.

Checklist:

• Securely signed commits
• Component(s) with PHPDoc blocks, only if necessary or adds value
• Unit testing, with >80% coverage
• User guide updated
• Conforms to style guide

[kenjis]

Thank you!

How about this?

--- a/user_guide_src/source/database/configuration.rst
+++ b/user_guide_src/source/database/configuration.rst
@@ -66,16 +66,6 @@ add the config variables as a query string:
     database character set), which are present in the rest of the configuration
     fields, CodeIgniter will append them.
 
-Configuring a MySQL socket connection
--------------------------------------
-
-To connect to a MySQL server over a filesystem socket, the path to the socket should be specified in 
-the ``'hostname'`` setting. CodeIgniter's MySQLi driver will notice this and configure the 
-connection properly.
-
-.. literalinclude:: configuration/011.php
-    :lines: 11-18
-
 Failovers
 ---------
 
@@ -200,3 +190,19 @@ Explanation of Values:
     etc.) not all values will be needed. For example, when using ``SQLite3`` you
     will not need to supply a username or password, and the database name
     will be the path to your database file.
+
+MySQLi
+======
+
+hostname
+--------
+
+Configuring a Socket Connection
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+To connect to a MySQL server over a filesystem socket, the path to the socket should be specified in
+the ``'hostname'`` setting. CodeIgniter's MySQLi driver will notice this and configure the
+connection properly.
+
+.. literalinclude:: configuration/011.php
+    :lines: 11-18

Before:

After:

[tangix]

@kenjis Hmmm... I seem to have messed up your changes and haven't found a way to undo that... Sigh.

[kenjis]

What's wrong? It seems okay.

[tangix]

What's wrong? It seems okay.

Yeah, now... I haven't really understood the GitHub magic and my GitKraken client gives me a hard time.
I think all looks good now.

[kenjis]

@tangix Thank you!