Add contributor section to 2020 landing page

[rviscomi]

Now that we've published the 2020 Contributors page, we could add the related section to the landing page to highlight the number of contributors.

Not having a "featured chapter" section makes the design a bit awkward because there's not a lot of room below the angled header background graphic. I've mocked up a version of the 2020 landing page without the alt-bg inverted styles on the contributor section:

Open to other design ideas!

Related issue: #1082

[tunetheweb]

To save redesigning this, what about something else in the Featured Quote section instead?

What about quotes/praise about the 2019 edition? Didn't you have a list somewhere?

[rviscomi]

That'd require some redesigning of the feature chapter section too, but that also works for me. Let me know which approach you'd prefer.

[tunetheweb]

Completed in #1383