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/chefs_knife.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="M10.04 8.29L6.68 12.02C1.73 7.56 -0.13 3.64 1.12 0.26L10.04 8.29ZM7.61 9.49C4.76 6.85 2.84 4.67 1.86 2.94C1.78 4.94 3.37 7.49 6.63 10.58L7.61 9.49L7.61 9.49ZM10.39 8.65L13.74 11.66C14.35 12.21 14.4 13.16 13.85 13.78C13.3 14.39 12.35 14.44 11.74 13.89L11.74 13.88L11.37 13.54C11.55 12.89 11.34 12.18 10.83 11.73L9.05 10.13L10.39 8.65Z"/>
+</svg>