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/scaffold.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="M6 12L8.67 10L6 8L6 12ZM6 13.25L6 14L5 14L5 13.01C5 13 5 13 5 12.99L5 10L2 10L2 14L1 14L1 1L2 1L2 2L13 2L13 1L14 1L14 6.99C14 7 14 7 14 7.01L14 12.99C14 13 14 13 14 13.01L14 14L13 14L13 13.25L9.5 10.63L6 13.25ZM12.67 7L6.33 7L9.5 9.38L12.67 7L12.67 7ZM13 8L10.33 10L13 12L13 8ZM5 7.01L5 7L2 7L2 9L5 9L5 7.01C5 6.9 5.03 6.79 5.1 6.7C5.27 6.48 5.58 6.43 5.8 6.6L6.33 7L5 7.01ZM6 4L6 6L13 6L13 4L6 4ZM5 4L2 4L2 6L5 6L5 4Z"/>
+</svg>