feat: add conference URL support for virtual meetings

bin/utils.ml

@@ -215,6 +215,15 @@ let get_description ev =
       | _ -> None)
     ev.props
 
+let get_conference_url ev =
+  List.find_map
+    (fun prop ->
+      match prop with
+      | `Xprop (("", "GOOGLE-CONFERENCE"), _, url) -> Some url
+      | `Xprop (("", "MICROSOFT-SKYPETEAMSMEETINGURL"), _, url) -> Some url
+      | _ -> None)
+    ev.props
+
 let separate_master_and_recurrence (events : Icalendar.event list) : Icalendar.event * Icalendar.event list =
   (* List.iteri (fun i e -> Printf.eprintf "%02d: %s\n" (i + 1) (Icalendar.show_component (`Event e))) events; *)
   let recur_ids = List.map (fun ev -> (ev, get_recurrence_id ev)) events in