<https://ja.getdocs.org/#/schema/person/image/>
<http://schema.org/contentUrl>
<https://secure.gravatar.com/avatar/b642b4217b34b1e8d3bd915fc65c4452?s=96&d=retro&r=g>
<https://ja.getdocs.org/how-to-set-up-a-website-hit-counter-with-redis-and-php-on-ubuntu-20-04>