Jekyll setup part 1

As described here: https://help.github.com/articles/using-jekyll-with-pages
1. 'Gemfile' created as described
2. 'bundle install'

the lock file is also included as it apperas to be recommended to include it, even
if it is not strictly nescessary. Maybe it will cause problems for users on
different platforms but i am not sure about that.
Documented Install

short instructions how to get started
Added example jekyll project

Generated with with:
'bundle exec jekyll new .'