Add SEO metadata tags and social sharing cards

[andrewheiss]

Right now the site doesn't have any meta tags like <meta name="description" ...> or <meta name="author" ...> tags, which hurts SEO and search engine rankings.

It might also be helpful (and SEOful) to add Open Graph tags to make it so articles that are shared on FB and Twitter get better previews. Though that's just for Facebook; Twitter uses their own Card standard

If you look at the source for andrewheiss.com you can see all these tags in action.

These additions would probably go in _includes/head.html

[lecy]

These are good ideas, I have a couple of questions. We can chat in August.