message: app-backend: more docs for options
diff: @@ -26,7 +26,22 @@ import fs from 'fs-extra';
  export interface RouterOptions {
  config: Config;
  logger: Logger;
  +
  + /**
  + * The name of the app package that content should be served from. The same app package should be
  + * added as a dependency to the backend package in order for it to be accessible at runtime.
  + *
  + * In a typical setup with a single app package this would be set to 'app'.
  + */
  appPackageName: string;
  +
  + /**
  + * A request handler to handle requests for static content that are not present in the app bundle.
  + *
  + * This can be used to avoid issues with clients on older deployment versions trying to access lazy
  + * loaded content that is no longer present. Typically the requests would fall back to a long-term
  + * object store where all recently deployed versions of the app are present.
  + */
  staticFallbackHandler?: express.Handler;
  }
  