Bump mdast from 2.3.2 to 3.0.0

Bumps [mdast](https://github.com/wooorm/mdast) from 2.3.2 to 3.0.0.
- [Release notes](https://github.com/wooorm/mdast/releases)
- [Commits](https://github.com/wooorm/mdast/commits/3.0.0)

---
updated-dependencies:
- dependency-name: mdast
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>