Update CONTRIBUTING.md

Point to discourse, rather than mailing lists.
Based on a suggestion by sujiniku,

https://gitlab.gnome.org/GNOME/gtk/-/merge_requests/1763

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 713c259190b432299a54b9abb76b5b822fa821aa..474598fc81baebadfd9d59ad1f5819b5c4b8d813 100644 (file)
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -22,12 +22,7 @@ Please, do not use the issue tracker for support questions. If you have
 questions on how to use GTK effectively, you can use:
 
  - the `#gtk` IRC channel on irc.gnome.org
- - the [gtk](https://mail.gnome.org/mailman/listinfo/gtk-list) mailing list,
-   for general questions on GTK
- - the [gtk-app-devel](https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list)
-   mailing list, for questions on application development with GTK
- - the [gtk-devel](https://mail.gnome.org/mailman/listinfo/gtk-devel-list)
-   mailing list, for questions on developing GTK itself
+ - the [gtk tag on the GNOME Discourse instance](https://discourse.gnome.org/tag/gtk)
 
 You can also look at the GTK tag on [Stack
 Overflow](https://stackoverflow.com/questions/tagged/gtk).