Override default markup and styles of taxonomy module

This patch removes Drupal core’s taxonomy.css and changes the markup from this:

<div class="term-listing-heading">
  <div id="taxonomy-term-1" class="taxonomy-term vocabulary-tags">
    <div class="content">
      <div class="taxonomy-term-description">
        <p>This is the description for this example taxonomy term.</p>
      </div>  
    </div>
  </div>
</div>

To this:

<article class="taxonomy-term taxonomy-term--tags taxonomy-term--full" role="article">
  <div class="taxonomy-term__content">
    <p>This is the description for this example taxonomy term.</p>
  </div>
</article>