title: Pandoc HTML to DOCX: how to correctly specify the alternative text of an image
body: <p>When converting an HTML file to a DOCX file with Pandoc, I would have expected that the <code>alt</code> attribute of an image would be converted to the image caption (with "Image Caption" style) in a DOCX file. But this doesn't seem to be the case.</p>
  
  <p>It only seems to work for me with Markdown's syntax: with <code>![alt text](xxx.jpg)</code>, the alt text is converted to an "Image Caption" styled element in Word.</p>
  
  <p>But I don't get it to work with HTML, even a <code>&lt;figure&gt;</code>'s <code>&lt;figcaption&gt;</code> is only converted to a standard paragraph, not to an "Image Caption" style in Word.</p>
  
  <p>How should it be done in HTML?</p>