Add Microformats (#3052)

* Add rel=me to author profile links

* Add h-card Microformats markup

* Add h-entry microformat markup

* Fix missing anchor tag

* Fix h-entry microformat markup on single template

* Use minimal subset of Microformat elements

* Move dt-published to `page__date.html` and remove dt-updated
* Remove "author" and "summary"

Leaves "url" as a hidden element

* Add page link to h1 tag

The h1 tag now contains the Schema-org `url` itemprop and the
Microformats `url` class in an anchor tag.  The anchor tag is styled to
not look like a link.

* Put author 'u-url' on author__name h3

This also puts the same `{{ author.home | default: '/' | absolute_url }}`
construct on `author__avatar` to remove the Jekyll `author.home`
conditional.

Also addresses SCSS text color error.

_includes/category-list.html

@@ -12,7 +12,7 @@
     <strong><i class="fas fa-fw fa-folder-open" aria-hidden="true"></i> {{ site.data.ui-text[site.locale].categories_label | default: "Categories:" }} </strong>
     <span itemprop="keywords">
     {% for category_word in categories_sorted %}
-      <a href="{{ category_word | slugify | prepend: path_type | prepend: site.category_archive.path | relative_url }}" class="page__taxonomy-item" rel="tag">{{ category_word }}</a>{% unless forloop.last %}<span class="sep">, </span>{% endunless %}
+      <a href="{{ category_word | slugify | prepend: path_type | prepend: site.category_archive.path | relative_url }}" class="page__taxonomy-item p-category" rel="tag">{{ category_word }}</a>{% unless forloop.last %}<span class="sep">, </span>{% endunless %}
     {% endfor %}
     </span>
   </p>