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/maki/ferry-JP.svg

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg width="15" height="15" viewBox="0 0 15 15" xmlns="http://www.w3.org/2000/svg" id="ferry-JP">
+  <path d="M9.5 12.5H5.5L5.5 8C5.5 6.91153 6.07979 5.44812 6.85389 4.13809C7.07346 3.76652 7.29495 3.43049 7.5 3.1451C7.70505 3.43049 7.92654 3.76652 8.14611 4.13809C8.92021 5.44812 9.5 6.91153 9.5 8V12.5ZM7.5 1C7 1 4 5 4 8V12.5C4 13.3284 4.67157 14 5.5 14H9.5C10.3284 14 11 13.329 11 12.5006V8C11 5 8 1 7.5 1Z"/>
+</svg>