i18n adjustments

[hulkoba]

Todo:

• Impressum: add Simone
• https://greenkeeper.io/de/datenschutzerklaerung: add Simone
• Footer: jumps around
• Greenkeeper: GitHub svg is 40x40, other: 33.35 x 33.35
• Header: Greenkeeper is not clickable on 'How it Works'
• Horizontal scrollbar
• Footer: inconsistent
• Browserlanguagedetection