Issue #133: Added instructions to create migration

Signed-off-by: alexmerlin <[email protected]>

Author: alexmerlin

docs/book/v6/installation/doctrine-orm.md

@@ -1,16 +1,36 @@
 # Doctrine ORM
 
-## Setup database
+This step saves the database connection credentials in an API configuration file.
+We do not cover the creation steps of the database itself.
 
-Use an existing empty one or create a new **MariaDB**/**MySQL** database.
+## Setup database
 
-> Recommended collation: `utf8mb4_general_ci`.
+Create a new **MariaDB**/**MySQL** database and set its collation to `utf8mb4_general_ci`.
+
+Make sure you fill out the database credentials in `config/autoload/local.php` under `$databases['default']`.
+Below is the item you need to focus on:
+
+```php
+$databases = [
+    'default' => [
+        'host'     => 'localhost',
+        'dbname'   => 'my_database',
+        'user'     => 'my_user',
+        'password' => 'my_password',
+        'port'     => 3306,
+        'driver'   => 'pdo_mysql',
+        'charset'  => 'utf8mb4',
+        'collate'  => 'utf8mb4_general_ci',
+    ],
+    // you can add more database connections into this array
+];
+```
 
-With a database created, fill out the database connection params in `config/autoload/local.php` under `$databases['default']`.
+> `my_database`, `my_user`, `my_password` are provided only as an example.
 
 ### Creating migrations
 
-Create a new migration by running:
+Create a database migration by executing the following command:
 
 ```shell
 php ./vendor/bin/doctrine-migrations diff
@@ -20,17 +40,37 @@ The new migration file will be placed in `src/Core/src/App/src/Migration/`.
 
 ### Running migrations
 
-Execute a new migration by running:
+Run the database migrations by executing the following command:
 
 ```shell
 php ./vendor/bin/doctrine-migrations migrate
 ```
 
-This command will prompt you to confirm that you want to run it:
+> If you have already run the migrations, you may get the below message:
+
+```text
+WARNING! You have x previously executed migrations in the database that are not registered migrations.
+  {migration list}
+Are you sure you wish to continue? (y/n)
+```
+
+> In this case, you should double-check to make sure the new migrations are ok to run.
 
-> WARNING! You are about to execute a migration in database "..." that could result in schema changes and data loss. Are you sure you wish to continue? (yes/no) [yes]:
+When using an empty database, you will get this confirmation message:
+
+```text
+WARNING! You are about to execute a migration in database "<your_database_name>" that could result in schema changes and data loss. Are you sure you wish to continue? (yes/no)
+```
 
 Hit `Enter` to confirm the operation.
+This will run all the migrations in chronological order.
+Each migration will be logged in the `migrations` table to prevent running the same migration more than once, which is often not desirable.
+
+If everything ran correctly, you will get this confirmation.
+
+```text
+[OK] Successfully migrated to version: Core\App\Migration\VersionYYYYMMDDHHMMSS
+```
 
 ### Executing fixtures