Updates Large Page Data error message doc to use JSON.parse to make reading output easier (#56713)

Fixes vercel/feedback#26361

Author: manovotny

errors/large-page-data.mdx

@@ -13,7 +13,7 @@ Reduce the amount of data returned from `getStaticProps`, `getServerSideProps`,
 To inspect the props passed to your page, you can inspect the below element's content in your browser devtools:
 
 ```bash filename="Terminal"
-document.getElementById("__NEXT_DATA__").text
+JSON.parse(document.getElementById("__NEXT_DATA__").textContent)
 ```
 
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