Init templates should scaffold contributing.md

[boazsender]

Github just introduced a nice feature that shows contribution guidelines to contributors when they try to contribute if you include a contributing.md file in the root of your repo:

https://github.com/blog/1184-contributing-guidelines

Grunt init tasks currently put contribution guidelines in a readme.md file. Instead, contribution guidelines should go in the newly supported contributing.md file.

[shama]

+1

[tkellen]

Great idea! This will be addressed in the templates for grunt .4. Also, further discussion about this should happen over at grunt-init.