chore(deps-dev): bump prettier from 2.3.1 to 2.4.0 in /docs

Bumps [prettier](https://github.com/prettier/prettier) from 2.3.1 to 2.4.0.
- [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/2.3.1...2.4.0)

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

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

docs/package.json

@@ -50,7 +50,7 @@
     "mustache": "^4.2.0",
     "null-loader": "^4.0.0",
     "prebuild-webpack-plugin": "^1.1.1",
-    "prettier": "2.3.1",
+    "prettier": "2.4.0",
     "string-replace-loader": "^3.0.3",
     "typescript": "^4.2.3",
     "webpack": "^5.46.0",