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/hangar.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="M13 13L13 7.5C13 7.22 12.78 7 12.5 7L2.5 7C2.22 7 2 7.22 2 7.5L2 13L0 13L0 9.5C0 5.36 3.36 2 7.5 2C11.64 2 15 5.36 15 9.5L15 13L13 13ZM3.5 5C3.22 5 3 5.22 3 5.5C3 5.78 3.22 6 3.5 6L6.5 6C6.78 6 7 5.78 7 5.5C7 5.22 6.78 5 6.5 5L3.5 5ZM8.5 5C8.22 5 8 5.22 8 5.5C8 5.78 8.22 6 8.5 6L11.5 6C11.78 6 12 5.78 12 5.5C12 5.22 11.78 5 11.5 5L8.5 5ZM3 12L7 12L7 13L3 13L3 12ZM3 10L7 10L7 11L3 11L3 10ZM3 8L7 8L7 9L3 9L3 8ZM8 8L12 8L12 9L8 9L8 8ZM8 10L12 10L12 11L8 11L8 10ZM8 12L12 12L12 13L8 13L8 12Z"/>
+</svg>