split intro section into two

creating a placeholder for a proper introduction, and a section
to describe our selection criteria for what we will map in
this document
dedented data citation components
adding numbering to data element sections
fixing horizontal rules in introduction
separating JATS existing from JATS modified

in one section separating what it would look like between
explicitly calling out a section with usage from
JATS as it is now, to a modified version of JATS
change of terminology required->suggested
adding JATS headding to sections
adding a section for layout of the document
draft introduction section
added a title
updated introduction
layout section
citation element overview
encoding on some spaces
adding list of fields
removed original fields para
fill in suggested section for authors
new sections, and formatting of headings

JATS citation section added

formatting of tags in headings added

fixing of hr rules applied

removal of modificaion sections that are empty