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/capitol.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="M7 1L9 0L11 1L13 0L13 3L11 4L9 3L8 3.5L8 5L7 5L7 1ZM2.5 9L12.5 9L12.5 15L2.5 15L2.5 9ZM4 10L4 14L5 14L5 10L4 10ZM7 10L7 14L8 14L8 10L7 10ZM10 10L10 14L11 14L11 10L10 10ZM2.5 8.5C2.75 5.97 4.89 4 7.5 4C10.11 4 12.25 5.97 12.5 8.5L2.5 8.5Z"/>
+</svg>