Add Danger plugin to readme

README.md

@@ -29,6 +29,7 @@ To get this up and running, install it using pip: `pip install proselint`.
 - [x] [Emacs via Flycheck](https://github.com/amperser/proselint/tree/master/plugins/flycheck) (thanks to [Aaron Jacobs](https://github.com/atheriel))
 - [x] [Vim](https://github.com/amperser/proselint/tree/master/plugins/vim) (thanks to [Matthias Bussonnier](https://github.com/Carreau))
 - [x] [Phabricator's `arc` CLI](https://github.com/google/arc-proselint) (thanks to [Jeff Verkoeyen](https://github.com/jverkoey))
+- [x] [Danger](https://github.com/dbgrandi/danger-prose) (thanks to [David Grandinetti](https://github.com/dbgrandi) and [Orta Therox](https://github.com/orta)) 
 
 ### Usage