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/bicycle_structure.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="M8.5 3.5L9.5 3.5C9.78 3.5 10 3.72 10 4L10 5.79L10.73 6.52C12 6.64 13 7.7 13 9C13 10.37 11.87 11.5 10.5 11.5C9.13 11.5 8 10.37 8 9C8 7.98 8.62 7.1 9.5 6.71L9.1 6.3L6.63 7.71C6.86 8.09 7 8.53 7 9C7 10.37 5.87 11.5 4.5 11.5C3.13 11.5 2 10.37 2 9C2 7.63 3.13 6.5 4.5 6.5C4.7 6.5 4.9 6.53 5.09 6.58L4.66 5.5L4.43 5.5C3.75 5.51 3.75 4.49 4.43 4.5L6.45 4.5C7.13 4.49 7.13 5.51 6.45 5.5L5.74 5.5L6.25 6.78L9 5.21L9 4.5L8.5 4.5C7.82 4.51 7.82 3.49 8.5 3.5ZM4.5 7.5C3.67 7.5 3 8.17 3 9C3 9.83 3.67 10.5 4.5 10.5C5.33 10.5 6 9.83 6 9C6 8.17 5.33 7.5 4.5 7.5ZM10.5 7.5C9.67 7.5 9 8.17 9 9C9 9.83 9.67 10.5 10.5 10.5C11.33 10.5 12 9.83 12 9C12 8.17 11.33 7.5 10.5 7.5ZM11.5 13L11 12L13 12L14 14L1 14L2 12L4 12L3.5 13L11.5 13ZM11.5 2L3.5 2L4 3L2 3L1 1L14 1L13 3L11 3L11.5 2Z"/>
+</svg>