update Model::has() and Model::hasNo() with where condition

Author: kevindees

v5/relationships.md

@@ -351,4 +351,13 @@ ExampleModel::new()->has('publishedBlog', function(Blog $query) {
         $query->where("{$table}.post_status", 'draft');
     });
 })->get();
+```
+
+Further, you can define the existence where condition as `OR`:
+
+```php
+ExampleModel::new()
+    ->where('name', 'kevin')
+    ->has('tags', null, 'OR')
+    ->get();
 ```