Final steps to finish off Hugo version reflecting new site design

[anjackson]

It's basically working and pushing to the hugo branch publishes itself here: https://ukwa-data-site.netlify.com/

There's a few things that need finishing off.

• The logo should be one of these! https://github.com/ukwa/ukwa-site/tree/master/logos
• The front page looks a bit weird because of how the big logo dominates the page.
• The pages for each dataset still have some cruft* in them

* Cruft like {% include cite_doi.md %} and odd formatting of links to metadata files.

But we also need to review it/compare it against the current version and look for any other problems or gaps.