Update Readme with official extension badge.

See micheleg#842.

Author: micheleg

README.md

@@ -4,7 +4,9 @@
 ## A dock for the GNOME Shell
 This extension enhances the dash moving it out of the overview and transforming it in a dock for an easier launching of applications and a faster switching between windows and desktops without having to leave the desktop view.
 
-For installation instructions and more information visit [https://micheleg.github.io/dash-to-dock/](https://micheleg.github.io/dash-to-dock/).
+[<img src="https://micheleg.github.io/dash-to-dock/media/get-it-on-ego.png" height="100">](https://extensions.gnome.org/extension/307/dash-to-dock)
+
+For additional installation instructions and more information visit [https://micheleg.github.io/dash-to-dock/](https://micheleg.github.io/dash-to-dock/).
 
 ## Installation from source