[seahorse] Update README to point to discourse.gnome.org

[Niels De Graef <nielsdg src gnome org>]

commit 130d392f0e4fddbf7d8bb5b2b27f1b0e6e8d166e
Author: Niels De Graef <nielsdegraef gmail com>
Date:   Sat Jun 13 10:50:17 2020 +0200

    Update README to point to discourse.gnome.org
    
    We're archiving the seahorse-list mailing list, so update the README to
    reflect that.

 README.md | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)
---
diff --git a/README.md b/README.md
index 3bf1c507..9fa26e33 100644
--- a/README.md
+++ b/README.md
@@ -31,8 +31,9 @@ the [translation project wiki page].
 ## More information
 Seahorse has its own web page on https://wiki.gnome.org/Apps/Seahorse.
 
-To discuss issues with developers and other users, you can subscribe to the
-[mailing list] or join [#seahorse] on irc.gnome.org.
+To discuss issues with developers and other users, you can go to [GNOME's
+Discourse instance] and use the "seahorse" tag, or join [#seahorse] on
+irc.gnome.org.
 
 ## License
 Seahorse is released under the GPL. See [COPYING] for more info.
@@ -44,6 +45,6 @@ Seahorse is released under the GPL. See [COPYING] for more info.
 [help pages on MR's]: https://docs.gitlab.com/ee/gitlab-basics/add-merge-request.html
 [issue tracker]: https://gitlab.gnome.org/GNOME/seahorse/issues
 [translation project wiki page]: https://wiki.gnome.org/TranslationProject/
-[mailing list]: https://mail.gnome.org/mailman/listinfo/seahorse-list
+[GNOME's Discourse instance]: https://discourse.gnome.org
 [#seahorse]: irc://irc.gnome.org/seahorse
 [COPYING]: https://gitlab.gnome.org/GNOME/seahorse/COPYING