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/balance_beam.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="M14.5 11C14.78 11 15 11.22 15 11.5L15 12.5C15 12.78 14.78 13 14.5 13L14 13L14 15L13 15L13 13L2 13L2 15L1 15L1 13L0.5 13C0.22 13 0 12.78 0 12.5L0 11.5C0 11.22 0.22 11 0.5 11L14.5 11ZM12.25 3.5C12.66 3.5 13 3.84 13 4.25C13 4.66 12.66 5 12.25 5L9 5L9 6.63L9.59 8.41L10.74 8.79C11.1 8.91 11.31 9.28 11.24 9.64L11.21 9.74C11.09 10.1 10.72 10.31 10.36 10.24L10.26 10.21L8.76 9.71C8.57 9.65 8.41 9.51 8.33 9.33L8.29 9.24L7.85 7.91L6.75 8.46L6.75 10C6.75 10.38 6.47 10.69 6.1 10.74L6 10.75C5.62 10.75 5.31 10.47 5.26 10.1L5.25 10L5.25 8C5.25 7.75 5.37 7.52 5.57 7.38L5.66 7.33L7 6.66L7 5L3.75 5C3.34 5 3 4.66 3 4.25C3 3.84 3.34 3.5 3.75 3.5L12.25 3.5ZM8 0C8.83 0 9.5 0.67 9.5 1.5C9.5 2.33 8.83 3 8 3C7.17 3 6.5 2.33 6.5 1.5C6.5 0.67 7.17 0 8 0Z"/>
+</svg>