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/solid/baby.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 384 512"><!--! 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="M120 88a72 72 0 1 1 144 0 72 72 0 1 1 -144 0zM7.7 144.5c13-17.9 38-21.8 55.9-8.8L99.8 162c26.8 19.5 59.1 30 92.2 30s65.4-10.5 92.2-30l36.2-26.4c17.9-13 42.9-9 55.9 8.8s9 42.9-8.8 55.9l-36.2 26.4c-13.6 9.9-28.1 18.2-43.3 25l0 36.3-192 0 0-36.3c-15.2-6.7-29.7-15.1-43.3-25L16.5 200.3c-17.9-13-21.8-38-8.8-55.9zM97.5 329.3l60.6 53-26 37.2 24.3 24.3c15.6 15.6 15.6 40.9 0 56.6s-40.9 15.6-56.6 0l-48-48C38 438.6 36.1 417 47.2 401.1l50.2-71.8zm128.5 53l60.6-53 50.2 71.8c11.1 15.9 9.2 37.5-4.5 51.2l-48 48c-15.6 15.6-40.9 15.6-56.6 0s-15.6-40.9 0-56.6l24.3-24.3-26-37.2z"/></svg>