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/hot_drink_cup.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="M3 2L4 0L11 0L12 2L12.5 2C12.78 2 13 2.22 13 2.5L13 3.5C13 3.78 12.78 4 12.5 4L12 4L11 15L4 15L3 4L2.5 4C2.22 4 2 3.78 2 3.5L2 2.5C2 2.22 2.22 2 2.5 2L3 2L3 2ZM10.82 6L11 4L4 4L4.19 6L10.82 6L10.82 6ZM10.27 12L4.73 12L4.91 14L10.09 14L10.27 12L10.27 12Z"/>
+</svg>