Add class comments to appease linter

Author: fredden

app/code/Magento/Indexer/Block/Backend/Grid/Column/Renderer/ScheduleStatus.php

@@ -10,6 +10,9 @@
 use Magento\Framework\Mview\View;
 use Magento\Framework\Phrase;
 
+/**
+ * Renderer for 'Schedule Status' column in indexer grid
+ */
 class ScheduleStatus extends AbstractRenderer
 {
     /**

app/code/Magento/Indexer/Block/Backend/Grid/Column/Renderer/Scheduled.php

@@ -5,6 +5,9 @@
  */
 namespace Magento\Indexer\Block\Backend\Grid\Column\Renderer;
 
+/**
+ * Renderer for 'Scheduled' column in indexer grid
+ */
 class Scheduled extends \Magento\Backend\Block\Widget\Grid\Column\Renderer\AbstractRenderer
 {
     /**

app/code/Magento/Indexer/Block/Backend/Grid/Column/Renderer/Status.php

@@ -5,6 +5,9 @@
  */
 namespace Magento\Indexer\Block\Backend\Grid\Column\Renderer;
 
+/**
+ * Renderer for 'Status' column in indexer grid
+ */
 class Status extends \Magento\Backend\Block\Widget\Grid\Column\Renderer\AbstractRenderer
 {
     /**

app/code/Magento/Indexer/Block/Backend/Grid/Column/Renderer/Updated.php

@@ -5,6 +5,9 @@
  */
 namespace Magento\Indexer\Block\Backend\Grid\Column\Renderer;
 
+/**
+ * Renderer for 'Updated' column in indexer grid
+ */
 class Updated extends \Magento\Backend\Block\Widget\Grid\Column\Renderer\Datetime
 {
     /**