Redesign Website

• Use new logo
• Use Deja Vu font
• Add bulma css framework
• Introduce a sticky nav bar and a footer
• Introduce a blog for updates

These are probably the main changes, but there are a lot of other small things that I've changed too. Please have a look and let me know what you think.

https://schleuder.org/dev/review/schleuder-website/nina-redesign/

closes #48 (closed)

Once merged I'd like to create a follow up issue to introduce a pagination for the blog.