nit: corrected upstream PR number

Author: ranjithrajv

README.md

@@ -1,7 +1,7 @@
 > [!IMPORTANT]  
 > This is not an offically maintained fork of [Exo](https://github.com/exo-explore/exo).
 > <br> The sole reason for this fork appears to be stalled maintenance of the project.
-> <br> PRs are welcome in the hopes that this fork remains stable and will be eventually merged [upstream](https://github.com/exo-explore/exo/pull/825).
+> <br> PRs are welcome in the hopes that this fork remains stable and will be eventually merged [upstream](https://github.com/exo-explore/exo/pull/852).
 > <br> No claim of ownership or future claim of stewardship is being made.
 > <br> No warranty is provided for this fork; use at your own risk.