Ignore Thumbs.db on Windows
Updating 404-page
feed.xml set to DE
Clean-Up2
Minimal changes to _config.yml (no private content)
Changing footer: Impress and privacy policy added

according to German law
Some redesigns made in _layout.scss

1. removed round border around site-logo
2. feature image pulled up to top
3. smaller heading
4. .center-class for inline centering in markdown