Improving README

* Converted to markdown and updated the formatting a little bit.
* Added Badges for RubyGems and CodeClimate

Preview:
https://github.com/BukhariH/hoe/blob/6eaa9f0690940815e2fac007d062892ef056b307/README.md

It's a wonderful gem and I would love for more people to dive in and start using Hoe :smile: