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/fontawesome/brands/dailymotion.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 448 512"><!--! Font Awesome Free 7.3.1 by @fontawesome - https://fontawesome.com License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License) Copyright 2026 Fonticons, Inc. --><path fill="currentColor" d="M298.9 267c-7.4-4.2-15.8-6.3-24.4-6.2-13.2 0-24.4 4.4-33.4 13.3s-13.6 20-13.6 33.4c0 14.1 4.4 25.6 13.3 34.6s20 13.4 33.4 13.4c13.7 0 25-4.6 34.1-13.8S322 321.1 322 307.5c0-8.2-2.1-16.3-6.1-23.5-4-7.1-9.8-13-17-17zM0 32l0 448 448 0 0-448-448 0zM374.7 405.3l-53.1 0 0-23.9-.7 0c-10.5 17.5-29.1 26.2-55.8 26.2-18.4 0-34.7-4.4-48.9-13.1-14.1-8.6-25.5-21-32.9-35.8-7.7-15.1-11.6-32.1-11.6-50.9 0-18.4 3.9-35.1 11.8-50.2 7.5-14.7 18.9-27.1 32.9-35.8 14.1-8.7 30-13.1 47.7-13.1 10.2-.1 20.2 1.6 29.7 5.2 8.9 3.5 17.2 9.1 25 17l0-77.9 55.8-12.1 0 264.4z"/></svg>