The Markdown widget is a text entry field that accepts GitHub-flavored Markdown text. Kibana renders the text you enter in this field and displays the results on the dashboard. You can click the Help link to go to the help page for GitHub flavored Markdown. Click Apply to display the rendered text in the Preview pane or Discard to revert to a previous version.
You are looking at preliminary documentation for a future release. Not what you want? See the current release documentation.