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/curtains.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="M3.02 9.49C2.59 9.3 1.97 8.9 1.19 8.31L1 8.17L1 1.5C1 1.22 1.22 1 1.5 1L7 1L7 2.28C7 5.21 5.5 7.93 3.02 9.49ZM5 14L1.5 14C1.22 14 1 13.78 1 13.5L1 9.41C1.51 9.79 2.14 10.15 2.87 10.5L3.05 10.6C4.26 11.31 5 12.6 5 14ZM11.98 9.49C9.5 7.93 8 5.21 8 2.28L8 1L13.5 1C13.78 1 14 1.22 14 1.5L14 8.17L13.81 8.31C13.03 8.9 12.41 9.3 11.98 9.49ZM10 14C10 12.6 10.74 11.31 11.95 10.6L12.13 10.5C12.86 10.15 13.49 9.79 14 9.41L14 13.5C14 13.78 13.78 14 13.5 14L10 14Z"/>
+</svg>