Update docusaurus

[paarthenon]

I'm pleased with the docs in progress, but the project is on version 2.4.1 while the current release of Docusaurus is 3.5.

• Search to see if there is a recommended upgrade path
• Attempt an incremental upgrade
• Failing that, attempt to re-home the markdown files in a 3.5 instance (this may be a larger task)

This should not block release unless there are compatibility or security implications to using the older version.