Validate docc content as part of background indexing #2153
Description
Is your feature request related to a problem? Please describe.
I write a lot of docc content in our packages (both doc comments and docc articles), and often I make a typo in a reference. Today, I don't catch these bugs until I open a PR, and our CI that validates the docc content catches it. Then I need to fix it, push, which restarts all the CI jobs, etc.
Describe the solution you'd like
It'd be great if VS Code validated the docc content just like we get build warnings/errors using background indexing as we type, without needing to explicitly trigger anything. It's okay if it's an opt-in setting, but I'd be very interested in this.
Basically the functionality that you get when you use the swift-docc-plugin and you ask it to analyze the content - it both validated doc comments, as well as articles in your docc bundle.
I'd want normal warnings to show up next to code warnings, in the VS Code sidebar.
Describe alternatives you've considered
Manually triggering docc validation - I do that today, and it's quite tedious.
Additional context