Add withHtml builder callback.

Author: yajra

buttons-extended.md

@@ -35,12 +35,14 @@ TO
 ## Quick Example:
 ```php
 Route::get('datatable', function(RolesDataTable $dataTable){
-   return $dataTable->before(function (Yajra\Datatables\Engines\BaseEngine $dataTable) {
+   return $dataTable->before(function (\Yajra\Datatables\Engines\BaseEngine $dataTable) {
        return $dataTable->addColumn('test', 'added inside controller');
-   })->response(function (Illuminate\Support\Collection $response) {
+   })->response(function (\Illuminate\Support\Collection $response) {
        $response['test'] = 'Append Data';
 
        return $response;
+   })->withHtml(function(\Yajra\Datatables\Html\Builder $builder) {
+        $builder->columns(['id', 'name', 'etc...']);
    })->render('path.to.view');
 });
 ```