Add 'written by' field, implement possibility for multiple authors

[jessesquires]

Currently, would use post.author for the written by field.

Written by:

• Appears below issue # and date, "Written by "

Add authors to _config.yml ?

authors:
    jesse: 
        name: 'Jesse Squires'
        url: 'twitter.com/jesse_squires'
   john:
        name: 'john appleseed'
        url: 'twitter.com/johnappleseed'

[jessesquires]

found solution here:
https://gist.github.com/ravasthi/1834570