Add forum link

Author: DogmaDragon

plugins/GroupDetails/GroupDetails.yml

@@ -1,7 +1,7 @@
 name: Group Details
 description: Adds group-card metrics for filtered duration and average vertical resolution.
 version: 0.2.3
-url: https://github.com/stashapp/CommunityScripts/tree/main/plugins/GroupDetails
+url: https://discourse.stashapp.cc/t/group-details/6819
 ui:
   javascript:
     - images.js

plugins/GroupDetails/README.md

@@ -1,5 +1,7 @@
 # Group Details
 
+https://discourse.stashapp.cc/t/group-details/6819
+
 `Group Details` is a UI plugin for Stash group card.
 
 ## Screenshot