That's pretty darn cool. I can see all of your services and endpoints without having to click through a bunch of menus in a gui, and discover some I might not have thought to ask for on my own - like "There's a PostMan collection? Great!". Nice idea.
Whats the point of doing this? I am curious now
It's just an easter egg in case someone accidentally clicks on api.docspring.com or sends an API request without a path. I thought it would be more fun than a generic 404 error like this: