Add info for data grid widget visibility in Toolbox

Added an alert about the Dojo widget and React client setting for the data grid widget.

Author: nayanaramdas

content/en/docs/refguide/modeling/integration/rest-services/consumed-rest-services/server-side-paging.md

@@ -77,6 +77,8 @@ Now, you can start calling the REST service from your microflow data source. To
 
 ## Creating a Data Grid with a Microflow Data Source
 
+{{% alert color="info" %}} The data grid widget is a Dojo widget and runtime setting 'Use React client' must be set to 'No' for it be visible in Toolbox. {{% /alert %}}
+
 In the previous section, you created a microflow which returns a list of characters. Now, you will use this microflow as a data source for a data grid:
 
 1. From the **Toolbox**, drag a **Data grid** onto a page.