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/sign_and_pedestrian.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="M11.5 4.25C11.5 4.94 10.94 5.5 10.25 5.5C9.56 5.5 9 4.94 9 4.25C9 3.56 9.56 3 10.25 3C10.94 3 11.5 3.56 11.5 4.25ZM9 5.75L9.75 5.75L14 8.73L14 9.42L13.5 9.42L11 7.64L11 9.42L12 11.25L13 13.54L12.5 14L12 14L11 11.71L9 8.96L9 6.82L7.75 7.81L6.75 9.42L6 9.42L6 8.96L6.75 7.58L9 5.75ZM9.42 10.52L8.27 14L7.75 14L7.25 13.54L8.66 9.67L9.42 10.52ZM2 3L3.5 3C3.78 3 4 3.22 4 3.5C4 3.78 3.78 4 3.5 4L2 4L2 3ZM2 2L2 6L5 6L5 2L2 2ZM2 1L5 1C5.55 1 6 1.45 6 2L6 6C6 6.55 5.55 7 5 7L2 7C1.45 7 1 6.55 1 6L1 2C1 1.45 1.45 1 2 1ZM3 7.5L4 7.5L4 14L3 14L3 7.5Z"/>
+</svg>