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

Leaves "url" as a hidden element

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.

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.