Bump remark-slug from 7.0.1 to 8.0.0

Bumps [remark-slug](https://github.com/remarkjs/remark-slug) from 7.0.1 to 8.0.0.
- [Release notes](https://github.com/remarkjs/remark-slug/releases)
- [Commits](remarkjs/remark-slug@7.0.1...8.0.0)

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

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