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/shoe.svg

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg xmlns="http://www.w3.org/2000/svg" width="15" height="15" viewBox="0 0 15 15" id="shoe">
+  <path d="M9.5,7a9.97,9.97,0,0,1-1.315-.948L6.01,3.221a.558.558,0,0,0-1,.279H5V5H3.209a.5.5,0,0,1-.357-.148S2.5,4,2,4H1.5a.5.5,0,0,0-.5.5V9H6.5c1.5,0,2,1,3.5,1h4V9.5C14,8,10.547,7.594,9.5,7Zm0,4a3.131,3.131,0,0,1-1.526-.447A4.1,4.1,0,0,0,6,10H1v1.5a.5.5,0,0,0,.5.5h4a.5.5,0,0,0,.5-.5V11a3.134,3.134,0,0,1,1.526.447A4.1,4.1,0,0,0,9.5,12h4a.5.5,0,0,0,.5-.5V11Z"/>
+</svg>