Update interpreter and example

packages/interpreter/src/interpreter.js

@@ -334,6 +334,7 @@ export function serialize_event(event) {
         location,
         repeat,
         which,
+        code,
       } = event;
       return {
         char_code: charCode,
@@ -347,6 +348,7 @@ export function serialize_event(event) {
         repeat: repeat,
         which: which,
         locale: "locale",
+        code,
       };
     }
     case "focus":