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/globe.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="globe">
+  <path d="M11.981,9.481,11.26,8.76A4.979,4.979,0,1,1,4.24,1.74l-.721-.721A5.991,5.991,0,0,0,7,11.475V13H6.5a.5.5,0,0,0,0,1h2a.5.5,0,0,0,0-1H8V11.473A5.983,5.983,0,0,0,11.981,9.481ZM7.5,9A3.5,3.5,0,1,0,4,5.5,3.5,3.5,0,0,0,7.5,9Zm1-5,.364-.592a2.5,2.5,0,0,1,.823.9L9.5,5h-1ZM6.656,3.156,7.5,4V5L8,6H9.94a2.494,2.494,0,0,1-1.5,1.814L8,7H6.5L5.05,5A2.5,2.5,0,0,1,6.656,3.156Z"/>
+</svg>