exclude some internal files from site generation
do not gitignore Gemfile.lock
Rakefile to push and publish to gh-pages
Add Gemfile.lock to git
Introduce simple english navigation
use hpstr-jekyll-theme

https://github.com/mmistakes/hpstr-jekyll-theme
Give credits to HPSTR Theme
front page title
footer: Impressum, Datenschutz
config
some more static files from HPSTR theme
use abstract image
show articles list
merge Rakefile into Rakefile.rb
Change navi
Use sky image on front page