Demo: hide the stall-reposition leg; re-record README GIF on the featured trip

The 0.1 km Langkampfen reposition is dropped from the embedded trip,
so drives are d1500-d1503. The README GIF now tours the real trip:
the Livigno → Langkampfen leg with its alpine speed/battery trace,
the 250 kW Olomouc charging curve, and the full four-stop itinerary
in the trip summary. Share selection:
?sel=d1500,d1501,d1502,d1503,c2500,c2501,c2502,c2503

Author: Greg