Improve look and feel for the HTML

The HTML template I made during the unconf is real basic and not all that attractive. I consider making it look better a must-do.

• @maelle had a great idea of using Blogdown or Hugo to generate a more complex site around the JSON-LD

• I think it was @cboettig that thought we could automatically put some exploratory data viz type plots or [skimr](https://github.com/ropenscilabs/skimr) output on the page. This would be awesome! See also the cool work in codebook which does a really nice job of this already. Here's what skimr can do:

  ## Variable type: numeric 
  ##      variable missing complete   n mean   sd  p0 p25  p50 p75 p100     hist
  ##  Petal.Length       0      150 150 3.76 1.77 1   1.6 4.35 5.1  6.9 ▇▁▁▂▅▅▃▁
  ##   Petal.Width       0      150 150 1.2  0.76 0.1 0.3 1.3  1.8  2.5 ▇▁▁▅▃▃▂▂
  

• At the very least, make the pages look as good as pkgdown's output. @cboettig mentioned showing a two-column display so the geo coverage and data access are at the top and less of the content is below the fold. I ❤️ ily agree.