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/mineshaft_profile.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 7L9.87 7C9.95 7 10.04 6.98 10.12 6.93L10.88 6.5C11 6.43 11.05 6.26 10.97 6.13C10.93 6.05 10.84 6 10.74 6L7 6L7 1L13 1C13.55 1 14 1.45 14 2L14 13C14 13.55 13.55 14 13 14L2 14C1.45 14 1 13.55 1 13L1 2C1 1.45 1.45 1 2 1L4 1L4 11.5C4 11.78 4.22 12 4.5 12L6.5 12C6.78 12 7 11.78 7 11.5L7 10L11.87 10C11.95 10 12.04 9.98 12.12 9.93L12.88 9.5C13 9.43 13.05 9.26 12.97 9.13C12.93 9.05 12.84 9 12.74 9L7 9L7 7Z"/>
+</svg>