title: Align image caption with image in asciidoc
body: <p>I have a block image inserted as shown below:</p>
  
  <pre><code>[[myimage]]
  image::fig1.png[align="center", title="My caption"]
  </code></pre>
  
  <p>Unfortunately, the image is centered but the caption is left-aligned. I also tried doing this:</p>
  
  <pre><code>[[myimage]]
  .My caption
  image::fig1.png[align="center"]
  </code></pre>
  
  <p>but the result does not change. How can I get the image caption to also be center-aligned?</p>
  
  <p>I am generating HTML output with this command (using xhtml11 as backend makes no difference):</p>
  
  <blockquote>
    <p>asciidoc -v -a asciimath -d article -b html5 -o file.html file.txt</p>
  </blockquote>