Genericize External Documentation

We use FreshService as our IT documentation repository and I am trying to integrate that with RDM's Documentation tab.

RDM supports External documentation > Service type: Custom but this only loads a login page.

Our previous documentation system was BookStack, which also would require authentication. I can't think of any IT documentation system that wouldn't require authentication, and all would be web-based. I am hoping there is a way to integrate this cleanly with RDM, since that's exactly what RDM does with other websites.

I could create a sub-entry of a website for documentation of an asset... but it just seems like RDM should have a way to do this without requiring Confluence or Sharepoint.

Clearly RDM already has everything necessary built-in to support logging in using the Session > Website entry, but for some reason the external Documentation configuration is designed to only support a very narrow subset of platforms.

If this could just be made more generic to support any website, ideally using the existing Website Session object type on the backend, it would immediately be both more useful to all customers and likely easier to maintain for developers (rather than supporting a dozen bespoke solutions).