Update screenshot.

README.md

@@ -84,7 +84,7 @@ with [Meteor](https://www.meteor.com).
 [platforms]: https://github.com/wekan/wekan/wiki/Platforms
 [dev_docs]: https://github.com/wekan/wekan/wiki/Developer-Documentation
 [screenshot_wekan]: http://i.imgur.com/cI4jW2h.png
-[screenshot_wefork]: https://wekan.github.io/screenshot.png
+[screenshot_wefork]: https://wekan.github.io/wekan-markdown.png
 [features]: https://github.com/wekan/wekan/wiki/Features
 [integrations]: https://github.com/wekan/wekan/wiki/Integrations
 [roadmap_wekan]: http://try.wekan.io/b/MeSsFJaSqeuo9M6bs/wekan-roadmap