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/statue.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="M9 9L9 11.5L6 11.5L6 9L4.73 9C4.45 9 4.23 8.78 4.23 8.5C4.23 8.44 4.24 8.38 4.26 8.32L5.86 5.03C5.95 4.86 6.12 4.75 6.31 4.75L8.69 4.75C8.88 4.75 9.05 4.86 9.14 5.03L10.74 8.32C10.84 8.58 10.71 8.87 10.45 8.97C10.4 8.99 10.34 9 10.27 9L9 9ZM11 12L11 13L12 13L12 14L3 14L3 13L4 13L4 12L11 12ZM7.5 1C8.33 1 9 1.67 9 2.5C9 3.33 8.33 4 7.5 4C6.67 4 6 3.33 6 2.5C6 1.67 6.67 1 7.5 1Z"/>
+</svg>