Update Rmd template to meet web accessibility standards #126
Description
Comment from @ajrgodfrey about the Rmd template:
It leads to a nice reading experience, but the HTML does not actually fully meet WCAG with for example too many heading level 1 tags on pages (sections are
<h1>and should be<h2>) so there is an opportunity to upgrade the template to the latest and best WCAG has to offer.