Syntax Documentation Improvements

[brian-ruf]

User Story:

As an OSCAL implementer, when reviewing the OSCAL syntax documents it would be helpful to have a summary of flags, fields, and assemblies first (as they appeared in the original version of the generated documentation), then followed by the expanded view as it appears now. This is especially important with larger assemblies. It is currently very difficult to find fields farther down in the assembly.

It would also be helpful to have improved visual delimiters as to where flags end and fields/sub-assemblies begin, as well as where the top-level assembly ends.

Goals:

• Increase usability by enabling a summary view of an assembly before the expanded view
• Provider better visual delimiters as to where one assembly ends and another begins, as well as within the assembly to differentiate flags from fields/sub-assemblies, and to further differentiate the child syntax of sub-assemblies.

Dependencies:

None.

Acceptance Criteria

• All website and readme documentation affected by the changes in this issue have been updated. Changes to the website can be made in the docs/content directory of your branch.
• A Pull Request (PR) is submitted that fully addresses the goals of this User Story. This issue is referenced in the PR.
• The CI-CD build process runs without any reported errors on the PR. This can be confirmed by reviewing that all checks have passed in the PR.

[wendellpiez]

Raises of how to address documentation enhancement improvement issues -- this might actually better be handled by OSCAL team since its scope is OSCAL documentation.

This Issue is flagged 'documentation' but it's not about Metaschema documentation, it is about XSLT M4 documentation generation. Maybe we need a flag for that?