message: message for empty chart readme
diff: @@ -9,7 +9,10 @@ interface IChartReadmeProps {
  class ChartReadme extends React.Component<IChartReadmeProps> {
  public render() {
  - const { markdown } = this.props;
  + let { markdown } = this.props;
  + if (markdown === "") {
  + markdown = "No README for this chart";
  + }
  return (
  <div className="ChartReadme">
  {markdown ? <ReactMarkdown source={markdown} /> : "Loading"}
  