Valid, semantic markup for in-page metadata (minimal version)

[Gordon Grace]

Refer:
https://github.com/govau/design-system-starter/blob/draft-media-release/docs/media-release/index.html#L163

Expected markup pattern using POSH:

<dl class="media-release__metadata">
  <dt>Published:</dt>
  <dd><time datetime="2019-04-10">10 April 2019</time></dd>
  <dt>Agency:</dt>
  <dd>Digital Transformation Agency</dd>
  <dt>Author:</dt>
  <dd>Kelly Smith</dd>
</dl>