40C3: tours, schedule data, tour map and calendar entries

- tour-map shortcode: Leaflet map of the tour locations with routes from the
  Congress, from the map/tours sections of data/schedule/<event>.yaml; Leaflet
  and the OSMIC, Maki and Temaki icon sets vendored; 39C3 uMap data converted.
- calendar shortcode: per tour date, a pill with an .ics download (iCalendar)
  and a Google Calendar link; Font Awesome Free vendored, fa-icon partial.
- README sections for the calendar and tour map shortcodes and the map data.

assets/vendor/icons/temaki/carport.svg

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg viewBox="0 0 15 15" version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
+  <path d="M11 8C11.55 8 12 8.45 12 9L12 12L11 12L11 13C11 13.55 10.55 14 10 14C9.45 14 9 13.55 9 13L9 12L6 12L6 13C6 13.55 5.55 14 5 14C4.45 14 4 13.55 4 13L4 12L3 12L3 9C3 8.45 3.45 8 4 8L4.89 5.34C4.96 5.14 5.15 5 5.36 5L9.64 5C9.85 5 10.04 5.14 10.11 5.34L11 8ZM5 11C5.55 11 6 10.55 6 10C6 9.45 5.55 9 5 9C4.45 9 4 9.45 4 10C4 10.55 4.45 11 5 11ZM5 8L10 8L9.38 6L5.62 6L5 8ZM10 11C10.55 11 11 10.55 11 10C11 9.45 10.55 9 10 9C9.45 9 9 9.45 9 10C9 10.55 9.45 11 10 11ZM2 5.41L2 14L0 14L0 4.09L7.5 0.91L15 4.09L15 14L13 14L13 5.41L7.5 3.09L2 5.41Z"/>
+</svg>