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/tree_broadleaved.svg

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg version="1.1" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 15 15">
+  <path d="M14 5.75c0 -0.69 -0.38 -1.32 -1 -1.61C12.95 3.49 12.4 3 11.75 3c-0.1 0 -0.2 0 -0.3 0c0 -0.66 -0.64 -1.15 -1.3 -1.09C9.9 2 9.65 2.11 9.46 2.25l0 0c0 -0.69 -0.56 -1.25 -1.25 -1.25S6.96 1.59 6.96 2.25C6.96 2.25 7 2.3 7 2.33C6.49 1.89 5.72 1.95 5.25 2.46C5.13 2.63 5 2.85 5 3C4.84 3 4.68 3 4.51 3C3.68 3 3 3.66 3 4.49C3 4.69 3 4.89 3.11 5C2.32 5.3 1.85 6.11 2 6.91C2.22 7.41 2.61 7.8 3.11 7.94c0.25 0.78 1.09 1.21 1.88 0.96C5.52 8.73 5.91 8.27 6 7.71C6.18 7.87 6.41 7.97 6.65 8v5L5 14h5l-1.6 -1v-2c0.74 -0.89 1.69 -1.58 2.77 -2c0.8 0.19 1.6 -0.31 1.79 -1.11C13 7.77 13 7.64 13 7.52c0 0 0 -0.11 0 -0.16C13.62 7 14 6.44 14 5.75zM8.4 10.25V6.82C8.67 7.3 9.18 7.6 9.73 7.6h0.25c0 0.44 0.22 0.85 0.57 1.12C9.76 9.09 9 9.62 8.4 10.25z"/>
+</svg>