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.

hugo.yaml

@@ -12,7 +12,7 @@ params:
     contact: "ticket@hackertours.hamburg.ccc.de"
     dateFormat: "02.01.2006 15:04"
     description: "Hamburg Hackertours"
-    footer: "[Impressum & Datenschutz](https://hamburg.ccc.de/imprint/) – [Ticket Shop](https://tickets.hamburg.ccc.de/hackertours/39c3ht/)"
+    footer: "[Impressum & Datenschutz](https://hamburg.ccc.de/imprint/) – [Ticket Shop](https://tickets.hamburg.ccc.de/hackertours/40c3ht/)"
     showPostDate: true
     logo: true
     logoPath: img/hackertours-2024-color.svg
@@ -33,7 +33,7 @@ languages:
     pagination:
       pagerSize: 25
     params:
-      footer: "[Imprint & Data Protection](https://hamburg.ccc.de/imprint/) – [Ticket Shop](https://tickets.hamburg.ccc.de/hackertours/39c3ht/)"
+      footer: "[Imprint & Data Protection](https://hamburg.ccc.de/imprint/) – [Ticket Shop](https://tickets.hamburg.ccc.de/hackertours/40c3ht/)"
     title: "Hamburg Hackertours"
     copyright: "[CCC Hansestadt Hamburg e.V.](https://hamburg.ccc.de) only acts as an agent for the tours. The respective tour operators are responsible for the offer and running of the tours."
   de: