Move main README to Wiki

[bartoszmajsak]

I think README should be brief entry point to anyone who just come across our repository. It should simply describe what it is and how to run it.

Details such as how to contribute and related guidelines as well as build options could be moved to GitHub wiki.

If you think it is a good idea I can do this.

[arun-gupta]

Yep, sounds like a great idea.

Lets keep README simple.

[aslakknutsen]

Add a CONTRIBUTING file to root that points to wiki

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

[bartoszmajsak]

Good point, thanks @aslakknutsen. Keen to create one? :)