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/cable.svg

@@ -0,0 +1,5 @@
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+<svg version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0" y="0" viewBox="0 0 15 15">
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+  <path d="M11 0.5C11 0 12.5 0 12.5 0.5C12.5 3 9.5 5.25 7.5 9.75C7.25 9.75 6.5 8.75 6.5 8.75C8.5 4.5 11 2.5 11 0.5zM10.25 5.75C9.75 6.5 9.5 6.75 9.25 7.25C9.25 8 9 8.5 8 10C7.75 10.5 9.25 10.5 9.5 10C10.5 8.75 10.75 8 10.25 5.75zM9.5 0.5C9.5 0 8 0 8 0.48C7.75 2 8 3.25 8.5 4.5C8.75 4.25 9.25 3.5 9.5 3C9.25 2 9.25 1.5 9.5 0.5zM4 0.5C4 3 5.5 4.5 7.5 6C7.25 6.5 7 7 6.65 7.5C4.5 5.75 2.5 3.5 2.5 0.5C2.5 0 4 0 4 0.5zM5 6.5C4.75 8 4.5 9 5.5 10C5.75 10.25 6.75 10.5 7.5 10.25C6 9 6 8.5 6.25 7.75C6 7.5 5.5 7 5 6.5zM7 0.5C7 0 5.5 0 5.5 0.5C5.75 1.75 6.25 2.75 6 4C6.25 4.5 6.75 5 7.25 5.25C7.75 3.5 7.25 2 7 0.5z"/>
+</svg>