VitePress markdown support with vue-tsc

[skirtles-code]

I'm trying to use vue-tsc to check my .md files in a VitePress project.

I have this working in VS Code with Volar (1.8.6, vue.server.vitePress.supportMdFile enabled). I don't know whether there's a similar setting for vue-tsc or how to pass such a setting if it does exist.

Based on 53315dd, it looks like it might have worked at some point in the past, but I'm unclear whether checking .md files with vue-tsc is currently supported.

Background: I have a pre-commit hook that I use to run type-checking on every commit. Currently the <script setup lang="ts"> sections in my .md files aren't being checked.

[skirtles-code]

I've had confirmation that this isn't currently supported, so I've opened a feature request at #3472.