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/hut.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="M9.15 8.82L11.13 9.93L12.2 8.86L13 9.12L13 15L9 15L9 11L6 11L6 15L2 15L2 9.12L2.8 8.86L3.87 9.93L5.85 8.82L7.5 10.61L9.15 8.82ZM9.15 4.91L11.15 5.91L11.85 5.21L15 9L12 8L11 9L9 7.88L7.5 9.5L6 7.88L4 9L3 8L0 9L3.15 5.22L3.85 5.91L5.85 4.91L7.5 6.56L9.15 4.91ZM7.5 0L12 4L11 5L9 4L7.5 5.5L6 4L4 5L3 4L7.5 0Z"/>
+</svg>