docs: move configuration details to separate file

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

docs/installation.md

@@ -16,15 +16,4 @@ You can publish the config file with this artisan command:
 php artisan vendor:publish --tag=laravel-wallet-config
 ```
 
-After installing the package, you can proceed to [use it](basic-usage).
-
-You can customize the configuration file to suit certain needs. Example: 
-
-Customize `name` and `slug` of default wallet.
-```php[config/wallet.php]
-'default' => [
-            'name' => 'Ethereum',
-            'slug' => 'ETH',
-            'meta' => [],
-        ],
-```
+After installing the package, you can proceed to [use it](basic-usage) or [configure](configuration) it to suit your needs.