[gnome-software.wiki] Update Software metadata

[Philip Withnall <pwithnall src gnome org>]

commit 0b440ab7f89adc1906da7e242fc92d447a46cfd5
Author: Philip Withnall <philip tecnocode co uk>
Date:   Thu Sep 9 14:38:11 2021 +0000

    Update Software metadata

 Software-metadata.md | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
---
diff --git a/Software-metadata.md b/Software-metadata.md
index b03f402..e2c1c42 100644
--- a/Software-metadata.md
+++ b/Software-metadata.md
@@ -97,7 +97,11 @@ You can improve the links:
 Carousel tile <a name="carousel-tile"></a>
 ---
 
-TODO
+<img align="right" src="uploads/9693635b79b479d9b69cbb2d82f8b15e/carousel.png">
+
+Applications which are featured by GNOME Software are displayed in a carousel at the top of the main window. 
Each carousel tile has a background colour which is automatically extracted from the application’s icon. 
Sometimes this background colour is not quite right for the application and needs to be specified explicitly 
by the application developer.
+
+The set of applications which are featured is decided by the Linux distribution maintainers.
 
 You can improve the carousel tile:
  * [How to set the carousel tile background 
colour](#user-content-how-to-set-the-carousel-tile-background-colour)