Use OpenAPI Specification language for better Documentation

[MarquiseRosier]

Is your feature request related to a problem? Please describe.
currently the documentation for the RUM API is a bit difficult to use; and work with.

Describe the solution you'd like
OpenAPI Specification language to generate documentation for the RUM API. Much easier to engage with; and for our end users!

Raised by David Barrat of the DAAS Team.

[dbrrt]

@MarquiseRosier Thanks for reporting it.
I'd not say RUM API is difficult to work with, but it's difficult to know what data points are available without OpenAPI specifications, without having to look at the code itself, which is not ideal from a consumer prospective.