Update frontend-forms.md (#1255)

Correction => syntax and structure errors in addField

Author: LSS-commits

dev/documentation/3.3/en/frontend-forms.md

@@ -189,14 +189,14 @@ HookRegistry::register('Form::config::before', function($hookName, $form) {
 
 	$form->removeField('subjects');
 
-	$form->addField(new \PKP\components\forms\FieldSelect('subjects') {
-		'label' => __('common.subjects'),
-		'isMultilingual' => true,
-		'options' => [
-			['value' => 'geology', 'label' => __('subject.geology'),
-			['value' => 'physics', 'label' => __('subject.physics'),
-		],
-	});
+	$form->addField(new \PKP\components\forms\FieldSelect('subjects', [
+	    'label' => __('common.subjects'),
+	    'isMultilingual' => true,
+	    'options' => [
+	        ['value' => 'geology', 'label' => __('subject.geology')],
+	        ['value' => 'physics', 'label' => __('subject.physics')],
+	    ],
+	]));
 
 	return false;
 }
@@ -281,4 +281,4 @@ The UI Library includes an example of [conditional display](/dev/#/component/For
 
 ---
 
-Learn about another complex component, [ListPanels](./frontend-list-panels), in the next section.
+Learn about another complex component, [ListPanels](./frontend-list-panels), in the next section.