Add the Mozilla Addons badge to the Readme.

README.md

@@ -2,6 +2,8 @@
 
 > **A WebExtension providing interactive guided tours of Tildes.**
 
+[![Get Tildes Shepherd for Firefox](./images/mozilla-addons.png)](https://addons.mozilla.org/firefox/addon/tildes-shepherd)
+
 ## Documentation
 
 * If you'd like to contribute to the tours, see [TOURS.md](TOURS.md).

TOURS.md

@@ -8,16 +8,4 @@ Draw it in GIMP, sketch it on paper and take a picture, as long as you can show
 
 ## Completion Status
 
-Below is a rough list of the planned tours together with which version of the WebExtension the tour is available in. Names and organization will likely change and differ from what's shown in the options page.
-
-If a tour is checked and has a version number it's available from Mozilla Addons right now. If it is checked and doesn't have a version number it's finished but hasn't yet been published. And if it's unchecked it hasn't been finished yet.
-
-* [x] Introduction (0.1.0)
-* [ ] Interface
-  * [x] Homepage (0.1.0)
-  * [ ] Account Settings
-  * [ ] Invites
-  * [ ] Groups
-  * [ ] Topics
-  * [ ] Comments
-  * [ ] Messages
+You can find a progress tracker [in this issue](https://git.bauke.xyz/tildes-community/tildes-shepherd/issues/4).