ticker: add terminal-digital

hosts/ticker/default.nix

@@ -341,6 +341,10 @@
           url = "https://talks.datenspuren.de/ds23/schedule/export/schedule.ics";
           color = "#DFDF2F";
         };
+        terminal-digital = {
+          url = "https://terminal.digital/?ical=1";
+          color = "#8787c4";
+        };
       };
     };
   };