Bump comrak from 0.17.1 to 0.18.0 (#237)

Bumps [comrak](https://github.com/kivikakk/comrak) from 0.17.1 to 0.18.0.
- [Release notes](https://github.com/kivikakk/comrak/releases)
- [Changelog](https://github.com/kivikakk/comrak/blob/main/changelog.txt)
- [Commits](kivikakk/comrak@0.17.1...0.18.0)

---
updated-dependencies:
- dependency-name: comrak
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

ext/commonmarker/Cargo.toml

@@ -5,7 +5,7 @@ edition = "2021"
 
 [dependencies]
 magnus =  "0.5"
-comrak = { version = "0.17", features = ["shortcodes"] }
+comrak = { version = "0.18", features = ["shortcodes"] }
 syntect = { version = "5.0", features = ["plist-load"] }
 
 [lib]