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/boat_repair.svg

@@ -0,0 +1,5 @@
+<?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="M12 3L5.79 3C5.4 2.12 4.52 1.5 3.5 1.5C2.48 1.5 1.6 2.12 1.21 3L3.5 3L4 4L3.5 5L1.21 5C1.6 5.88 2.48 6.5 3.5 6.5C4.52 6.5 5.4 5.88 5.79 5L12 5C12.55 5 13 4.55 13 4C13 3.45 12.55 3 12 3Z"/>
+  <path d="M13 10C12.93 11.83 11.93 12.77 10 12.82L3 12.82L2 10L10.02 10L8 8.5L9 8L12 10L13 10ZM5 9.5L2 9.5L2 8L4 8C4.55 8 5 8.45 5 9L5 9.5Z"/>
+</svg>