Support release notes in the Outline view

[legowerewolf]

I want the Outline panel to have a table of contents (like Markdown files do, for example) when I'm looking at the release notes.

[vs-code-engineering[bot]]

This feature request is now a candidate for our backlog. The community has 60 days to upvote the issue. If it receives 20 upvotes we will move it to our backlog. If not, we will close it. To learn more about how we handle feature requests, please see our documentation.

Happy Coding!

[mjbvz]

Duplicate of #148889