Beautify the rendering of members of att.global or any lengthy list of elements

[ebeshero]

This takes over the original ticket: #451 . The listing of all 580 elements (or indeed a whole lot of elements in the Guidelines) is a challenge for displaying usefully in the interface. We want this list to be present, but where we have a very long list of elements (more than 50), we can provide the viewer a choice to show all, or provide a minimal initial sampling to start. From the earlier ticket, we could try applying the <html:details> and <html:summary> elements.