[gnome-software] RELEASE.md: Add a link to gitlab-changelog

[Phaedrus Leeds <mwleeds src gnome org>]

commit 94c432f6cc9957b9cc978ce741081c4f7040a182
Author: Phaedrus Leeds <mwleeds endlessos org>
Date:   Fri Feb 12 18:00:13 2021 -0800

    RELEASE.md: Add a link to gitlab-changelog

 RELEASE.md | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
---
diff --git a/RELEASE.md b/RELEASE.md
index c6b722068..a6785a99e 100644
--- a/RELEASE.md
+++ b/RELEASE.md
@@ -25,7 +25,9 @@ git status
 
 Check the version in `meson.build` is correct for this release.
 
-Write release entries:
+Download
+[gitlab-changelog](https://gitlab.gnome.org/pwithnall/gitlab-changelog) and use
+it to write release entries:
 ```
 gitlab-changelog GNOME/gnome-software ${previous_version}..
 ```