Decorator in text editor for class to open related markdown

[fforjan]

Is your feature request related to a problem? Please describe.
We've started to add technical documentation with markdown (and mermaid) for some services/classes into our code base.
We've decided to have someething like:
MyClass.cs
MyClass.MD

or
MyService.cs
MyService.MD

But if the developer does not browse/check the solution tree, he/she/they is unfortunately not aware of the markdown document.

Describe the solution you'd like
Could we have a class 'decorator' into the code editor that, if a related markdown file is found, the user is aware of it and simply need to click it to open the related document in view mode - that should be the default view.

Describe alternatives you've considered
We've started to add code comment saying 'hey, please check the related MD' but it is still a bit painful to open it

Additional context
Add any other context or screenshots about the feature request here.