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/maki/amusement-park.svg

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg width="15" height="15" viewBox="0 0 15 15" xmlns="http://www.w3.org/2000/svg" id="amusement-park">
+  <path d="M13.5 7C13.5 9.02798 12.4939 10.821 10.9535 11.907L12 13.9999H3L4.04645 11.907C2.50613 10.821 1.5 9.02798 1.5 7C1.5 3.68629 4.18629 1 7.5 1C10.8137 1 13.5 3.68629 13.5 7ZM12.2984 7.125H8.99487C8.96844 7.4453 8.84138 7.73706 8.64538 7.96861L10.9814 10.3046C11.7719 9.47202 12.2669 8.35614 12.2984 7.125ZM10.8046 10.4814L8.46861 8.14538C8.33136 8.26156 8.17296 8.35351 8 8.41465V11.7743C9.08206 11.6623 10.0574 11.1908 10.8046 10.4814ZM6.00513 7.125H2.7016C2.73307 8.35614 3.2281 9.47202 4.01864 10.3046L6.35462 7.96861C6.15862 7.73706 6.03156 7.4453 6.00513 7.125ZM4.19542 10.4814C4.94259 11.1908 5.91794 11.6623 7 11.7743V8.41465C6.82704 8.35351 6.66864 8.26156 6.53139 8.14538L4.19542 10.4814ZM12.2984 6.875C12.2669 5.64386 11.7719 4.52798 10.9814 3.69542L8.64538 6.03139C8.84138 6.26294 8.96844 6.5547 8.99487 6.875H12.2984ZM10.8046 3.51864C9.97202 2.7281 8.85614 2.23307 7.625 2.2016V5.50513C7.9453 5.53156 8.23706 5.65862 8.46861 5.85462L10.8046 3.51864ZM7.375 5.50513V2.2016C6.14386 2.23307 5.02798 2.7281 4.19542 3.51864L6.53139 5.85462C6.76294 5.65862 7.0547 5.53156 7.375 5.50513ZM6.35462 6.03139L4.01864 3.69542C3.2281 4.52798 2.73307 5.64386 2.7016 6.875H6.00513C6.03156 6.5547 6.15862 6.26294 6.35462 6.03139Z"/>
+</svg>