docs: extending the base wallet class

Signed-off-by: Kekeocha Justin Chetachukwu <[email protected]>

docs/installation.md

@@ -17,7 +17,7 @@ php artisan vendor:publish --tag=laravel-wallet-config
 ```
 
 After installing the package, you can proceed to [use it](basic-usage).
-
+## Configure default wallet
 You can customize the configuration file to suit certain needs. Example: 
 
 Customize `name` and `slug` of default wallet.
@@ -28,3 +28,31 @@ Customize `name` and `slug` of default wallet.
             'meta' => [],
         ],
 ```
+## Extend Wallet class
+You can extend the Wallet class by creating a new class that extends `Bavix\Wallet\Models\Wallet` and registering the new class in config/wallet.php.
+Example `MyWallet.php`
+
+```php[App/Models/MyWallet.php]
+use Bavix\Wallet\Models\Wallet as WalletBase;
+
+class MyWallet extends WalletBase {
+    public function helloWorld(): string { return "hello world"; }
+}
+```
+
+```php[config/wallet.php]
+    'wallet' => [
+        'table' => 'wallets',
+        'model' => MyWallet::class,
+        'creating' => [],
+        'default' => [
+            'name' => 'Default Wallet',
+            'slug' => 'default',
+            'meta' => [],
+        ],
+    ],
+```
+```php
+   echo $user->wallet->helloWorld();
+```
+