Fixed itemAt to use GET

Author: sumurthy

api-reference/beta/api/tablerowcollection_itemat.md

@@ -6,8 +6,8 @@ The following **scopes** are required to execute this API:
 ### HTTP request
 <!-- { "blockType": "ignored" } -->
 ```http
-POST /workbook/tables(<id|name>)/rows/ItemAt
-POST /workbook/worksheets(<id|name>)/tables(<id|name>)/rows/ItemAt
+GET /workbook/tables(<id|name>)/rows/ItemAt(index=n)
+GET /workbook/worksheets(<id|name>)/tables(<id|name>)/rows/ItemAt(index=n)
 
 ```
 ### Request headers
@@ -29,20 +29,13 @@ If successful, this method returns `200, OK` response code and [TableRow](../res
 ### Example
 Here is an example of how to call this API.
 ##### Request
-Here is an example of the request.
+Here is an example of the request. Returns 1st row. 
 <!-- {
   "blockType": "request",
   "name": "tablerowcollection_itemat"
 }-->
 ```http
-POST https://graph.microsoft.com/beta/me/drive/items/<id>/workbook/tables(<id|name>)/rows/ItemAt
-Content-type: application/json
-Content-length: 20
-
-{
-  "index": {
-  }
-}
+GET https://graph.microsoft.com/beta/me/drive/items/<id>/workbook/tables(<id|name>)/rows/ItemAt(0)
 ```
 
 ##### Response
@@ -71,4 +64,4 @@ Content-length: 45
   "keywords": "",
   "section": "documentation",
   "tocPath": ""
-}-->
+}-->