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/maki/gaming.svg

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg height="15" viewBox="0 0 15 15" width="15" xmlns="http://www.w3.org/2000/svg" id="gaming">
+  <path d="m13.1 11.5c-.6.3-1.4.1-1.8-.5l-1.1-1.4h-5.40002l-1.1 1.4c-.5.7-1.4.8-2.1.3-.5-.4-.700004-1-.600004-1.5l.700004-3.7c.2-1.2 1.3-2.1 2.5-2.1h2.8v-1.5c0-.8.6-1.5 1.4-1.5h3.10002c.3 0 .5.2.5.5s-.2.5-.5.5h-3.00002c-.3 0-.5.2-.5.4v.1 1.5h2.80002c1.2 0 2.3.9 2.5 2.1l.7 3.7c.1.7-.2 1.4-.9 1.7zm-7.10002-5c0-.8-.7-1.5-1.5-1.5s-1.5.7-1.5 1.5.7 1.5 1.5 1.5 1.5-.7 1.5-1.5zm6.00002 0c0-.3-.2-.5-.5-.5h-.5v-.5c0-.3-.2-.5-.5-.5s-.50002.2-.50002.5v.5h-.5c-.3 0-.5.2-.5.5s.2.5.5.5h.5v.5c0 .3.20002.5.50002.5s.5-.2.5-.5v-.5h.5c.3 0 .5-.2.5-.5z"/>
+</svg>