NPM version added to the readme file

Author: alexcanessa

README.md

@@ -1,8 +1,11 @@
 # grunt-github-release-notes
 
+[![npm version](https://badge.fury.io/js/grunt-github-release-notes.svg)](https://badge.fury.io/js/grunt-github-release-notes)
+
 > Grunt module to publish release notes based on commits between the last two tags.
 This module is using [github-release-notes](https://github.com/alexcanessa/github-release-notes).
 
+
 ## Getting Started
 This plugin requires Grunt `~0.4.5`
 
@@ -42,4 +45,4 @@ There are optional arguments such as:
 - `draft: true` To set the release as a draft. Default: `false`
 - `prerelease: true` To set the release as a prerelease. Default: `false`
 - `prefix: 'v'` Add a prefix to the tag version `e.g. v1.0.1`.
-- `force: 'true'` Fails the task if the task presents any errors. Default: `false`
+- `force: 'true'` Fails the task if the task presents any errors. Default: `false`