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/wall.svg

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0" y="0" viewBox="0 0 15 15">
+  <path d="M6.5 8a0.5 0.5 0 0 1 0.5 0.5v1a0.5 0.5 0 0 1 -0.5 0.5h-3A0.5 0.5 0 0 1 3 9.5v-1A0.5 0.5 0 0 1 3.5 8ZM5 6.5a0.5 0.5 0 0 0 0.5 0.5h3A0.5 0.5 0 0 0 9 6.5v-1A0.5 0.5 0 0 0 8.5 5h-3a0.5 0.5 0 0 0 -0.5 0.5ZM8.5 11h-3a0.5 0.5 0 0 0 -0.5 0.5v1a0.5 0.5 0 0 0 0.5 0.5h3a0.5 0.5 0 0 0 0.5 -0.5v-1A0.5 0.5 0 0 0 8.5 11Zm5 -9h-2a0.5 0.5 0 0 0 -0.5 0.5v1a0.5 0.5 0 0 0 0.5 0.5H13V5H10.5a0.5 0.5 0 0 0 -0.5 0.5v1a0.5 0.5 0 0 0 0.5 0.5H13v4H10.5a0.5 0.5 0 0 0 -0.5 0.5v1a0.5 0.5 0 0 0 0.5 0.5h3a0.5 0.5 0 0 0 0.5 -0.5V2.5A0.5 0.5 0 0 0 13.5 2Zm-4 0h-3a0.5 0.5 0 0 0 -0.5 0.5v1a0.5 0.5 0 0 0 0.5 0.5h3a0.5 0.5 0 0 0 0.5 -0.5v-1A0.5 0.5 0 0 0 9.5 2Zm-5 0h-3a0.5 0.5 0 0 0 -0.5 0.5v10a0.5 0.5 0 0 0 0.5 0.5h2a0.5 0.5 0 0 0 0.5 -0.5v-1a0.5 0.5 0 0 0 -0.5 -0.5H2V7H3.5A0.5 0.5 0 0 0 4 6.5v-1A0.5 0.5 0 0 0 3.5 5H2V4H4.5A0.5 0.5 0 0 0 5 3.5v-1A0.5 0.5 0 0 0 4.5 2ZM8 8.5v1a0.5 0.5 0 0 0 0.5 0.5h3a0.5 0.5 0 0 0 0.5 -0.5v-1a0.5 0.5 0 0 0 -0.5 -0.5h-3A0.5 0.5 0 0 0 8 8.5Z"/>
+</svg>