Something along these lines should do it. This will prompt for dictation, and then append to the end of the current draft with a timestamp and the dictated text. It utilized template tags. The template
variable can be edited to change the format of the appended element.
// define a template
let template = `
# [[time]]
[[dictated-text]]
`;
// dictate
var s = editor.dictate();
if (s.length > 0) {
draft.setTemplateTag("dictated-text", s);
draft.content = draft.content + draft.processTemplate(template);
draft.update();
}