Add year of creation

[bennycode]

trafficstars

Some style guides might be more recent than others so I propose to add the year of style guide creation / last update to the list.

Example:

- [AngularJS](https://github.com/johnpapa/angular-styleguide) - John Papa (2014)

[lipis]

Interesting.. but it will be hard to maintain that info.. I would say if it's outdated or crap.. shouldn't be on the list :)