[gnome-boxes-logos] Update recommended-downloads.xml file

[Felipe Borges <felipeborges src gnome org>]

commit 4637f20d584999e562d46a8a63937a2f706f048c
Author: Felipe Borges <felipeborges gnome org>
Date:   Thu Aug 4 11:08:14 2022 +0200

    Update recommended-downloads.xml file
    
    See https://gitlab.gnome.org/GNOME/gnome-boxes/-/wikis/recommended-downloads.xml

 recommended-downloads.xml | 26 ++++++++++++++++++++++++--
 1 file changed, 24 insertions(+), 2 deletions(-)
---
diff --git a/recommended-downloads.xml b/recommended-downloads.xml
index 6ff2603..c9bd0f1 100644
--- a/recommended-downloads.xml
+++ b/recommended-downloads.xml
@@ -1,13 +1,35 @@
 <?xml version="1.0" encoding="utf-8" ?>
+<!--
+  These are operating systems listed in the recommended section of the
+  "Download an OS" page.
+
+  This list is powered by libosinfo, therefore the IDs are unique identifiers
+  for each OS in osinfo-db. Use "osinfo-query os" in the CLI to list all available
+  operating systems and their respective IDs.
+
+  Downstreams are encouraged to tweak the list as they wish. Sorting is also
+  available.
+
+  "title", "subtitle" and "url" can be overwritten by distributors.
+
+  Distributors can host their own recommended-downloads.xml file, and point to it
+  with the org.gnome.boxes recommended-downloads-url gsetting.
+
+  See https://gitlab.gnome.org/GNOME/gnome-boxes/-/wikis/recommended-downloads.xml
+ -->
 <list>
   <os id="http://redhat.com/rhel/"/>
   <os id="http://rockylinux.org/rocky/"/>
   <os id="http://fedoraproject.org/fedora/"/>
   <os id="http://fedoraproject.org/silverblue/"/>
   <os id="http://ubuntu.com/ubuntu/"/>
-  <os id="http://opensuse.org/opensuse/"/>
+  <os id="http://opensuse.org/opensuse/15.4"/>
   <os id="http://opensuse.org/opensuse/tumbleweed/"/>
   <os id="http://debian.org/debian/"/>
   <os id="http://endlessos.com/eos/"/>
-  <os id="http://gnome.org/gnome/nightly"/>
+  <os id="http://gnome.org/gnome/nightly";>
+    <title>GNOME OS Nightly</title>
+    <subtitle>The GNOME Project</subtitle>
+    <url>https://os.gnome.org/download/latest/gnome_os_installer.iso</url>
+  </os>
 </list>