make github.io page mobile friendly

[zeratax]

• [ ] on mobile devices stuff should be way bigger and
• [ ] overflow hiding should be done differently, see: https://stackoverflow.com/questions/14270084/overflow-xhidden-doesnt-prevent-content-from-overflowing-in-mobile-browsers
  • [x] also add a min-width to the buttons
  • [ ] add ograph and meta tags