OpenGraph Protocol is used by sites like Facebook to display a rich object in a social graph.
* Add OpenGraph Protocol to each page
Hugo has an internal template for [Open Graph](https://gohugo.io/templates/internal/#open-graph). It takes necessary information from either site's or post's config thus it makes sense to add it to each page.
* Add 'series' to posts archetype
This taxonomy is used to specify related “see also” pages by placing them in the same series.
* Add series taxonomy to exampleSite config.
* Add example of series to exampleSite
* Add spaz926 to Contributors
* Add Twitter Cards to each page
Hugo has an internal template for [Twitter Cards](https://gohugo.io/templates/internal/#twitter-cards). It takes necessary information from either site's or post's config thus it makes sense to add it to each page.
* Add 'description' to posts archetype
This optional field is used by Twitter Cards.
* Add example usage of Twitter Cards
* Add artspb to contributors
Joseph Ting
Jeffrey C
Artem Khvastunov
Luiz F. A. de Prá