layouts/shortcodes/page/header.html

{{ $title := $.Page.Params.title -}}
{{ $desc  := $.Page.Params.description | markdownify -}}
<div class="text-left">
  <h1 class="display-1 mb-5">
    {{- $title -}}
  </h1>

  {{- with $desc -}}
  <h3 class="font-weight-light">
    {{- . -}}
  </h3>
  {{ end -}}
</div>