Update README.md

Author: gracjan

README.md

@@ -7,6 +7,7 @@ This is an Emacs mode for editing, debugging and developing Haskell programs.
 [![Build Status](https://travis-ci.org/haskell/haskell-mode.svg?branch=master)](https://travis-ci.org/haskell/haskell-mode)
 [![Melpa Status](http://melpa.org/packages/haskell-mode-badge.svg)](http://melpa.org/#/haskell-mode)
 [![Melpa Stable Status](http://stable.melpa.org/packages/haskell-mode-badge.svg)](http://stable.melpa.org/#/haskell-mode)
+[![Latest Docs](http://img.shields.io/badge/docs-latest-fc1e5e.svg)](http://haskell.github.io/haskell-mode/manual/latest/)
 
 
 > I just want to thank everybody involved in one way or another with the Haskell Emacs tooling.