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/hedge.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 11.57L7.5 9.43L5 11.57L5 13L4 13L4 11.57L1.02 9.02L0.75 9.02C0.34 9.02 0 8.68 0 8.27L0 2.67C0 2.29 0.29 1.97 0.67 1.93L2.25 1.75C3.75 1.58 5.26 1.5 6.76 1.5L7.5 1.5L8.24 1.5C9.74 1.5 11.25 1.58 12.75 1.75L14.33 1.93C14.71 1.97 15 2.29 15 2.67L15 8.27C15 8.68 14.66 9.02 14.25 9.02L13.98 9.02L11 11.57L11 13L10 13L10 11.57ZM11 10.31L12.5 9L8.5 9L10 10.31L10 9L11 9L11 10.31ZM5 10.31L6.5 9L2.5 9L4 10.31L4 9L5 9L5 10.31Z"/>
+</svg>