* 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
Salvatore Giordano
Artem Khvastunov
Khosrow Moossavi
Luiz F. A. de Prá