[SPIKE]: look into supporting ReDoc in addition to DocFX

[dmccaffery]

The DocFX open-api / swagger documentation is very lackluster at present and has not been prioritized:

dotnet/docfx#2072
dotnet/docfx#465

This project looks very interesting:

https://github.com/Rebilly/ReDoc

We should consider supporting it automatically within condo for REST API documentation generation.