restructure liftoff, more features to track progress

_includes/liftoff_cookieinfo.html

_includes/liftoff_js.html

_includes/liftoff_mission.html

_includes/liftoff_nextpage.html

_includes/liftoff_progress.html

_layouts/liftoff.html

_liftoffmissions/liftoff_mission_ansprechen.md

_liftoffmissions/liftoff_mission_chaotikumaccount.md

_liftoffmissions/liftoff_mission_gruppentreffen.md

_liftoffmissions/liftoff_mission_icebox.md

_liftoffmissions/liftoff_mission_sticker.md

_liftoffmissions/liftoff_mission_tourguide.md

_liftoffmissions/liftoff_mission_wifi.md

assets/iceboxnav.gif

liftoff_chaos.md

liftoff_day1.md

liftoff_day4.md

liftoff_first_3dprint.md

liftoff_first_soldering.md

liftoff_first_wled.md