message: Improve error for non-JSON-API requests to API namespace endpoints
diff: @@ -40,7 +40,7 @@ export default class JSONAPIMiddleware {
  if (this.isJSONAPI(ctxt)) {
  return this.jsonHandlers(ctxt, next);
  } else {
  - throw new CardstackError(`not implemented`);
  + throw new CardstackError(`Only JSON-API requests are supported at this endpoint`);
  }
  };
  }
  