18f.gsa.gov: Automate bylines

Right now blog posts require the following to get a simple byline:

# in the frontmatter
authors:
- author1
- author2

and in the post body

<p class="authors">
  by {% author author1 %} and {% author author2 %}
</p>

Let's eliminate the redundancy and see if it's possible to auto-generate the byline in the post template. We accidentally publish too many posts without bylines.

Desired state:
Something like this in layouts/post.html

<p class="authors">{% authors %}</p>

Considerations:

• some of our posts have illustrators
• authors are available in the site object at: site.data.authors in templates. There are different ways to tap into this depending on what kind of plugin you're making.
• there are probably other Jekyll sites that have done this; I did it for a side project of mine, but that might not be the best model.