Create new lutaml_xsd default template for rendering XSD schemas in Metanorma

[ronaldtse]

From:

• Support data-driven documentation from XML Schema (XSD) annotations metanorma#441

Requires:

• Implement new lutaml_xsd command to allow accessing XSD files in Liquid #176

The UnitsML 1.0 XSD schema is at:

• https://github.com/unitsml/schemas

The XSD file contains annotations that is now generated into documentation published here ("official documentation"):

• https://schema.unitsml.org/docs/unitsml/unitsml-v1.0/

The goal here is to create a Metanorma document for UnitsML that achieves publication of the same in the CalConnect format.

This task is to create a Liquid template (see how the lutaml_express command works) that allows the user to access from Metanorma the annotations and necessary content (necessary content = what is seen at the "official documentation" now).

Notice that we need to generate the SVGs and interactive content (anchors, links) properly.