fix: change the link for Mux upgrade (#246)

Author: morgante

.grit/patterns/js/mux_v8.md

@@ -3,8 +3,7 @@ title: Upgrade Mux SDK to v8
 tags: [js, ts, npm, upgrade, mux, migration, stainless, mux, sdk]
 ---
 
-Upgrade the [Mux SDK](https://github.com/muxinc/mux-node-sdk) to [v8 with Stainless](https://github.com/stainless-sdks/mux-node)
-
+Upgrade the [Mux SDK](https://github.com/muxinc/mux-node-sdk) to [v8 with Stainless](https://github.com/muxinc/mux-node-sdk/releases/tag/v8.0.0)
 
 ```grit
 engine marzano(0.1)