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/golf_green.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="M4.5 10.16L4.5 11.46C3.85 11.54 3.25 11.71 3.25 12C3.25 12.45 4.63 12.6 5.5 12.6C6.37 12.6 7.75 12.45 7.75 12C7.75 11.71 7.15 11.54 6.5 11.46L6.5 10.02C6.82 10.01 7.16 10 7.5 10C12 10 15 11 15 12C15 13 12 14 7.5 14C3 14 0 13 0 12C0 11.24 1.72 10.49 4.5 10.16ZM5.5 0C5.78 0 6 0.22 6 0.5L6 12L5 12L5 0.5C5 0.22 5.22 0 5.5 0ZM6.5 0.5C7.03 1.01 7.67 1.4 8.41 1.68C9.15 1.95 10.85 2.15 13.5 2.27C11.98 3.85 10.71 4.84 9.68 5.22C8.66 5.59 7.6 5.59 6.5 5.22L6.5 0.5Z"/>
+</svg>