message: Clarify the config data is a reference
diff: @@ -18,7 +18,7 @@ import * as file_read from './file_read';
  import * as logging from './logging';
  export interface JsonConfig<T> {
  - // Returns the config data as a json object.
  + // Returns a reference (*not* a copy) to the json object backing the config.
  data(): T;
  // Writes the config to the backing storage.
  write();
  