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/anvil_and_hammer.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="M11 12.5L13 14L13 15L11 15C10.33 14.33 9.5 14 8.5 14C7.5 14 6.67 14.33 6 15L4 15L4 14L6 12.5L11 12.5ZM15 7L15 8C12.86 8 11.11 9.68 11 11.8L11 12L6 12C6 11.36 5.75 10.75 5.29 10.29L5 10L5 7L15 7ZM4.5 7.5L4.5 10C2.83 10 1.33 9.17 0 7.5L4.5 7.5ZM11.5 1C11.75 1 11.95 1.18 11.99 1.41L12 1.5L12 5.5C12 5.75 11.82 5.95 11.59 5.99L11.5 6L9.5 6C9.25 6 9.05 5.82 9.01 5.59L9 5.5L9 1.5C9 1.25 9.18 1.05 9.41 1.01L9.5 1L11.5 1ZM8.5 3L8.5 4L2.5 4C2.22 4 2 3.78 2 3.5C2 3.25 2.18 3.05 2.41 3.01L2.5 3L8.5 3Z"/>
+</svg>