Bump vuepress-plugin-mermaidjs from 1.8.1 to 1.9.0 (#55)

Bumps [vuepress-plugin-mermaidjs](https://github.com/eFrane/vuepress-plugin-mermaidjs) from 1.8.1 to 1.9.0.
- [Release notes](https://github.com/eFrane/vuepress-plugin-mermaidjs/releases)
- [Changelog](https://github.com/eFrane/vuepress-plugin-mermaidjs/blob/master/Changelog.md)
- [Commits](eFrane/vuepress-plugin-mermaidjs@v1.8.1...v1.9.0)

---
updated-dependencies:
- dependency-name: vuepress-plugin-mermaidjs
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

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

Author: dependabot[bot]