change configuration to new array syntax

database.md

@@ -21,21 +21,21 @@ Sometimes you may wish to use one database connection for SELECT statements, and
 
 To see how read / write connections should be configured, let's look at this example:
 
- 'mysql' => array(
-  'read' => array(
+ 'mysql' => [
+  'read' => [
   'host' => '192.168.1.1',
-  ),
-  'write' => array(
+  ],
+  'write' => [
   'host' => '196.168.1.2'
-  ),
+  ],
   'driver' => 'mysql',
   'database' => 'database',
   'username' => 'root',
   'password' => '',
   'charset' => 'utf8',
   'collation' => 'utf8_unicode_ci',
   'prefix' => '',
- ),
+ ],
 
 Note that two keys have been added to the configuration array: `read` and `write`. Both of these keys have array values containing a single key: `host`. The rest of the database options for the `read` and `write` connections will be merged from the main `mysql` array. So, we only need to place items in the `read` and `write` arrays if we wish to override the values in the main array. So, in this case, `192.168.1.1` will be used as the "read" connection, while `192.168.1.2` will be used as the "write" connection. The database credentials, prefix, character set, and all other options in the main `mysql` array will be shared across both connections.