integration-docs: Add missing example screenshots.

For Asana, Discourse, GitHub Actions, Phabricator, Puppet integrations
that previously did not have any example screenshots.

The screenshot images were generated in the prior commit.

templates/zerver/integrations/asana.md

@@ -17,4 +17,8 @@ Get Zulip notifications for your Asana projects via Zapier!
 
 {end_tabs}
 
+{!congrats.md!}
+
+![](/static/images/integrations/asana/001.png)
+
 [1]: ./zapier

templates/zerver/integrations/discourse.md

@@ -28,6 +28,10 @@ Forward new Discourse posts to Zulip!
 
 {end_tabs}
 
+{!congrats.md!}
+
+![](/static/images/integrations/discourse/001.png)
+
 ### Related documentation
 
 - [Discourse Chat Integration][chat-integration]

templates/zerver/integrations/github-actions.md

@@ -6,3 +6,7 @@ It's easy to send Zulip messages from GitHub Actions! This is useful:
 Instructions are available [here](https://github.com/zulip/github-actions-zulip#readme).
 
 See also the [GitHub integration](/integrations/doc/github).
+
+{!congrats.md!}
+
+![](/static/images/integrations/github-actions/001.png)

templates/zerver/integrations/notion.md

@@ -17,4 +17,8 @@ Get Zulip notifications for your Notion pages and databases via Zapier!
 
 {end_tabs}
 
+{!congrats.md!}
+
+![](/static/images/integrations/notion/001.png)
+
 [1]: ./zapier

templates/zerver/integrations/puppet.md

@@ -4,3 +4,7 @@ runs fail (or when they happen at all).
 1.  Follow the instructions
     [here](https://forge.puppetlabs.com/mbarr/puppet_zulip)
     to get it set up.
+
+{!congrats.md!}
+
+![](/static/images/integrations/puppet/001.png)