Use the Docusaurus-native sidebar configuration schema

[ptgott]

Currently, the prepare-files.mts script needs to convert the docs site configurations at config.json in each version of the docs to a format that Docusaurus can ingest. Let's replace the config.json format with this format so we don't need to perform the conversion.

Warning: the docspaths workflow in shared-workflows relies on the current structure of each docs version's config.json file. Other workflows might as well. Make sure nothing breaks when moving to the Docusaurus-native schema.

Steps:

• Edit scripts/prepare-files.mts to accept the Docusaurus config format as an input in addition to the legacy docs/config.json format
• Update the docpaths workflow to accept the Docusaurus config format in addition to the legacy format
• Migrate all docs/config.json files to the Docusaurus config format
• Edit scripts/prepare-files.mts to remove the configuration transformation and only move the config file to the new location.
• Update the docpaths workflow to only accept the Docusaurus config format

[ptgott]

Getting the new docs engine to accept both the old and new config structures:

@docusaurus/plugin-content-docs doesn't seem to export functions to validate instances of the SidebarsConfig type. However, there is code to validate the legacy config structure.

We can edit docusaurusifyNavigation (GitHub) to:

• Take an arbitrary object as an argument
• Attempt to validate the object as a legacy config
• If it's a legacy config, process it as normal
• If it's not a legacy config, leave it unchanged, with the assumption that Docusaurus will catch any failures.