message: fix font-family inside Markdown description iframe
diff: @@ -54,6 +54,7 @@ export class SyncMarkdownView extends React.Component<{content: string}, {}> {
  color: ${this.props.content ? '#333' : '#999'};
  background-color: transparent !important;
  min-width: auto !important;
  + font-family: "Open Sans",Helvetica,Arial,sans-serif
  }
  </style>
  <body><div>${markdownConvert(this.props.content || 'Not available')}</div></body>`;
  