Upgrade: Bump prettier from 2.7.0 to 2.8.0

Bumps [prettier](https://github.com/prettier/prettier) from 2.7.0 to 2.8.0.
- [Release notes](https://github.com/prettier/prettier/releases)
- [Changelog](https://github.com/prettier/prettier/blob/main/CHANGELOG.md)
- [Commits](https://github.com/prettier/prettier/compare/2.7.0...2.8.0)

---
updated-dependencies:
- dependency-name: prettier
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

package.json

@@ -15,7 +15,7 @@
     "@vuepress/plugin-debug": "^2.0.0-beta.25",
     "@vuepress/plugin-search": "^2.0.0-beta.25",
     "postcss-loader": "^7.0.0",
-    "prettier": "^2.7.0",
+    "prettier": "^2.8.0",
     "sass": "^1.51.0",
     "sass-loader": "^13.2.0",
     "vue-property-decorator": "^9.1.2",