Improve Developer Using Schematron and Understanding Results

[aj-stein-nist]

User Story

As a Metaschema developer, in order to better understand how can I modify Measchema-based model definitions and predict mistakes sooner and faster, I want clear documentation on how to use existing Schematrons to check my modified Metaschemas definitions and understand the results to make corrections.

Goals

• Add docs with inventory of existing Schematrons for Metaschema definition validations
• Document how to run them
• Document how to interpret results
• Document how to find results with errors in CI/CD (once implemented)

Dependencies

• Queries for schema documentation top-down polish OSCAL#801
• Lint Metaschema Definitions for Trailing and Leading Whitespace  #31
• Data Type Check in Metaschema Definitions #32
• Style Guide for OSCAL Documentation OSCAL#1185

Acceptance Criteria

• All Metaschema website and readme documentation affected by the changes in this issue have been updated. Changes to the Metaschema 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.

[GaryGapinski]

If editing constrained by XML Schema is employed for Metaschema document maintenance, consider using embedded Schematron within the related XML Schema to obtain timely identification of deficiencies.

Alternately, multiple xml-model PIs can be used to associate multiple schemas with an instance document.