Update publishing-config.md

Author: rmcdaniel

docs/configuration/publishing-config.md

@@ -56,3 +56,20 @@ It should now look like this.
 ```php
 'base_model' => MongoDB\Laravel\Eloquent\Model::class,
 ```
+
+## Changing Serializer
+
+This setting allows you to optionally use the Base64 serializer instead of Y (kind of like yEnc encoding where it only gets rid of null bytes). The tradeoff is between speed and size. Base64 is faster but adds more overhead. Y is slower but a lot smaller. If you change this it will only affect new workflows and old workflows will revert to whatever they were encoded with to ensure compatibility.
+
+The default serializer setting in `workflows.php` is:
+
+```php
+'serializer' => Workflow\Serializers\Y::class,
+```
+
+To use Base64 instead, update it to:
+
+```php
+'serializer' => Workflow\Serializers\Base64::class,
+```
+