title: markdown not using emmet
body: <p>I have included the following in my vs-code user settings:</p>
  
  <pre><code>"emmet.includeLanguages": {
    "vue-html": "html",
    "markdown": "html"
  },
  "emmet.triggerExpansionOnTab": true,
  </code></pre>
  
  <p>And would have expected to see <strong>emmet</strong> working for markdown files as an outcome but I get no suggestions and even if I explicitly press <code>⌃Space</code> it just comes up with "No Suggestions". </p>
  
  <p>What else is needed to get emmet in Markdown files?</p>