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/seesaw.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="M13 3.5C13.51 3.5 13.94 3.89 13.99 4.38L14 4.5L14 7C14.4 7 14.78 7.24 14.93 7.64C15.12 8.12 14.91 8.65 14.47 8.89L14.36 8.93L12 9.84L12 10C12 10.55 11.55 11 11 11C10.65 11 10.34 10.82 10.16 10.55L7.81 11.45L10.3 15L4.7 15L6.95 11.78L5 12.53L5 13C5 13.55 4.55 14 4 14C3.55 14 3.16 13.7 3.04 13.29L1.36 13.93C0.84 14.13 0.26 13.87 0.07 13.36C-0.12 12.88 0.09 12.35 0.53 12.11L0.64 12.07L1 11.93L1 8.5C1 7.95 1.45 7.5 2 7.5C2.51 7.5 2.94 7.89 2.99 8.38L3 8.5L3 9.72L3.76 9.53C3.82 9.52 3.87 9.51 3.92 9.5L4.02 9.5L4.02 9.5L4.07 9.5L4.07 9.5L4.18 9.52L4.18 9.52L4.29 9.54L4.29 9.54L4.42 9.59L4.42 9.59L4.46 9.61L4.46 9.61L4.55 9.66L4.55 9.66L4.66 9.75L4.66 9.75L4.76 9.85L4.76 9.85L4.8 9.89L4.8 9.89L4.86 9.99L4.86 9.99L4.91 10.09L4.91 10.09L4.96 10.2L4.96 10.2L4.98 10.32L4.98 10.32L4.99 10.39L10 8.47L10 7.44L10.01 7.39L10.01 7.39L10 7.5C10 7.4 10.01 7.31 10.04 7.22L10.09 7.08L10.09 7.08L10.13 7L10.13 7L10.21 6.89L10.21 6.89L10.29 6.79L10.39 6.71L10.39 6.71L10.45 6.66L10.45 6.66L10.53 6.62L10.53 6.62L10.68 6.55L10.68 6.55L10.76 6.53L12 6.22L12 4.5C12 3.95 12.45 3.5 13 3.5ZM2 4C2.83 4 3.5 4.67 3.5 5.5C3.5 6.33 2.83 7 2 7C1.17 7 0.5 6.33 0.5 5.5C0.5 4.67 1.17 4 2 4ZM13 0C13.83 0 14.5 0.67 14.5 1.5C14.5 2.33 13.83 3 13 3C12.17 3 11.5 2.33 11.5 1.5C11.5 0.67 12.17 0 13 0Z"/>
+</svg>