docs(flexgrid): fix story ID in mdx docs (#13126)

* docs(flexgrid): fix story ID in mdx docs

* docs(flexgrid): fix story ID in mdx docs

---------

Co-authored-by: kodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>

packages/react/src/components/Grid/FlexGrid.mdx

@@ -40,7 +40,7 @@ import { FlexGrid, Row, Column } from '@carbon/react';
 ```
 
 <Preview>
-  <Story id="components-flexgrid--responsive-grid" />
+  <Story id="elements-flexgrid--responsive-grid" />
 </Preview>
 
 ## Overview
@@ -85,7 +85,7 @@ we will use the `sm`, `md`, and `lg` prop to specify how many columns the
 `Column` components should span at the small, medium, and large breakpoints.
 
 <Preview>
-  <Story id="components-flexgrid--responsive-grid" />
+  <Story id="elements-flexgrid--responsive-grid" />
 </Preview>
 
 ## Grid modes
@@ -105,25 +105,25 @@ to mix-and-match certain grid modes to achieve a particular layout.
 ### Wide grid
 
 <Preview>
-  <Story id="components-flexgrid--full-width" />
+  <Story id="elements-flexgrid--full-width" />
 </Preview>
 
 ### Narrow grid
 
 <Preview>
-  <Story id="components-flexgrid--narrow" />
+  <Story id="elements-flexgrid--narrow" />
 </Preview>
 
 ### Condensed grid
 
 <Preview>
-  <Story id="components-flexgrid--condensed" />
+  <Story id="elements-flexgrid--condensed" />
 </Preview>
 
 ### Mix-and-match
 
 <Preview>
-  <Story id="components-flexgrid--mixed-grid-modes" />
+  <Story id="elements-flexgrid--mixed-grid-modes" />
 </Preview>
 
 ## Auto columns
@@ -143,7 +143,7 @@ components would span 50% each, four `Column` components would span 25% each,
 and so on.
 
 <Preview>
-  <Story id="components-flexgrid--auto-columns" />
+  <Story id="elements-flexgrid--auto-columns" />
 </Preview>
 
 ## Offset columns
@@ -164,7 +164,7 @@ breakpoint. At the medium breakpoint, it will be offset by two columns.
 ```
 
 <Preview>
-  <Story id="components-flexgrid--offset" />
+  <Story id="elements-flexgrid--offset" />
 </Preview>
 
 ## Component API